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0001 FN ISI Export Format 0002 VR 1.0 0003 PT J 0004 AU Colizza, V 0005 Barrat, A 0006 Barthelemy, M 0007 Vespignani, A 0008 TI The role of the airline transportation network in the prediction and 0009 predictability of global epidemics 0010 SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF 0011 AMERICA 0012 LA English 0013 DT Article 0014 DE complex systems; epidemiology; networks 0015 ID INFECTIOUS-DISEASE; MATHEMATICAL-MODEL; GEOGRAPHIC SPREAD; INFLUENZA; 0016 OUTBREAKS; TRAVEL 0017 AB The systematic study of large-scale networks has unveiled the 0018 ubiquitous presence of connectivity patterns characterized by 0019 large-scale heterogeneities and unbounded statistical fluctuations. 0020 These features affect dramatically the behavior of the diffusion 0021 processes occurring on networks, determining the ensuing statistical 0022 properties of their evolution pattern and dynamics. In this article, we 0023 present a stochastic computational framework for the forecast of global 0024 epidemics that considers the complete worldwide air travel 0025 infrastructure complemented with census population data. We address two 0026 basic issues in global epidemic modeling: (i) we study the role of the 0027 large scale properties of the airline transportation network in 0028 determining the global diffusion pattern of emerging diseases; and (ii) 0029 we evaluate the reliability of forecasts and outbreak scenarios with 0030 respect to the intrinsic stochasticity of disease transmission and 0031 traffic flows. To address these issues we define a set of quantitative 0032 measures able to characterize the level of heterogeneity and 0033 predictability of the epidemic pattern. These measures may be used for 0034 the analysis of containment policies and epidemic risk assessment. 0035 C1 Indiana Univ, Sch Informat, Bloomington, IN 47401 USA. 0036 Indiana Univ, Ctr Biocomplex, Bloomington, IN 47401 USA. 0037 Univ Paris 11, CNRS, Unite Mixte Rech 8627, F-91405 Orsay, France. 0038 RP Vespignani, A, Indiana Univ, Sch Informat, Bloomington, IN 47401 USA. 0039 EM alexv@indiana.edu 0040 CR ALBERT R, 2002, REV MOD PHYS, V74, P47 0041 ANDERSON RM, 1992, INFECT DIS HUMANS 0042 BAROYAN OV, 1969, B INT EPIDEMIOL ASS, V18, P22 0043 BARRAT A, 2004, P NATL ACAD SCI USA, V101, P3747 0044 CHOWELL G, 2003, PHYS REV E 2, V68 0045 CLIFF A, 2004, BRIT MED BULL, V69, P87 0046 COHEN ML, 2000, NATURE, V406, P762 0047 CRAIS RF, 2004, HLTH CARE MANAGE SCI, V7, P127 0048 DICKMAN R, 1994, PHYS REV E, V50, P4404 0049 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 0050 EUBANK S, 2004, NATURE, V429, P180 0051 FERGUSON NM, 2003, NATURE, V425, P681 0052 FLAHAULT A, 1991, MATH POPUL STUD, V3, P1 0053 GARDINER WC, 2004, HDB STOCHASTIC METHO 0054 GASTNER MT, 2004, P NATL ACAD SCI USA, V101, P7499 0055 GILLESPIE DT, 2000, J CHEM PHYS, V113, P297 0056 GRAIS RF, 2003, EUR J EPIDEMIOL, V18, P1065 0057 GUIMERA R, 2005, P NATL ACAD SCI USA, V102, P7794 0058 HETHCOTE HW, 1984, LECT NOTES BIOMATHS, V56, P1 0059 HUFNAGEL L, 2004, P NATL ACAD SCI USA, V101, P15124 0060 KEELING MJ, 1999, P ROY SOC LOND B BIO, V266, P859 0061 KRETZSCHMAR M, 1996, MATH BIOSCI, V133, P165 0062 LLOYD AL, 2001, SCIENCE, V292, P1316 0063 LONGINI IM, 1988, MATH BIOSCI, V90, P367 0064 MARRO J, 1998, NONEQUILIBRIUM PHASE 0065 MEYERS LA, 2005, J THEOR BIOL, V232, P71 0066 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 0067 PASTORSATORRAS R, 2003, EVOLUTION STRUCTURE 0068 RVACHEV LA, 1985, MATH BIOSCI, V75, P3 0069 ZIPF GK, 1949, HUMAN BEHAV PRINCIPL 0070 NR 30 0071 TC 24 0072 PU NATL ACAD SCIENCES 0073 PI WASHINGTON 0074 PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA 0075 SN 0027-8424 0076 J9 PROC NAT ACAD SCI USA 0077 JI Proc. Natl. Acad. Sci. U. S. A. 0078 PD FEB 14 0079 PY 2006 0080 VL 103 0081 IS 7 0082 BP 2015 0083 EP 2020 0084 PG 6 0085 SC Multidisciplinary Sciences 0086 GA 013LU 0087 UT ISI:000235411600005 0088 ER 0089 0090 PT J 0091 AU Colizza, V 0092 Flammini, A 0093 Serrano, MA 0094 Vespignani, A 0095 TI Detecting rich-club ordering in complex networks 0096 SO NATURE PHYSICS 0097 LA English 0098 DT Article 0099 ID INTERNET TOPOLOGY 0100 AB Uncovering the hidden regularities and organizational principles of 0101 networks arising in physical systems ranging from the molecular level 0102 to the scale of large communication infrastructures is the key issue in 0103 understanding their fabric and dynamical properties(1-5). The 0104 'rich-club' phenomenon refers to the tendency of nodes with high 0105 centrality, the dominant elements of the system, to form tightly 0106 interconnected communities, and it is one of the crucial properties 0107 accounting for the formation of dominant communities in both computer 0108 and social sciences(4-8). Here, we provide the analytical expression 0109 and the correct null models that allow for a quantitative discussion of 0110 the rich-club phenomenon. The presented analysis enables the 0111 measurement of the rich-club ordering and its relation with the 0112 function and dynamics of networks in examples drawn from the 0113 biological, social and technological domains. 0114 C1 Indiana Univ, Sch Informat, Bloomington, IN 47406 USA. 0115 Indiana Univ, Dept Phys, Bloomington, IN 47406 USA. 0116 RP Vespignani, A, Indiana Univ, Sch Informat, Bloomington, IN 47406 USA. 0117 EM alexv@indiana.edu 0118 CR ALBERT R, 2002, REV MOD PHYS, V74, P47 0119 AMARAL LAN, 2004, EUR PHYS J B, V38, P147 0120 BARABASI AL, 1999, SCIENCE, V286, P509 0121 BARRAT A, 2004, P NATL ACAD SCI USA, V101, P3747 0122 BIANCONI G, EMERGENCE LARGE CLIN 0123 BOGUNA M, 2003, PHYS REV E 2, V68 0124 BOGUNA M, 2004, EUR PHYS J B, V38, P205 0125 COLIZZA V, 2005, PHYSICA A, V352, P1 0126 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 0127 ERDOS P, 1959, PUBL MATH-DEBRECEN, V6, P290 0128 FALOUTSOS M, 1999, COMP COMM R, V29, P251 0129 GUIMERA R, 2005, NATURE, V433, P895 0130 GUIMERA R, 2005, P NATL ACAD SCI USA, V102, P7794 0131 GUIMERA R, 2005, SCIENCE, V308, P697 0132 MASLOV S, 2002, SCIENCE, V296, P910 0133 MOLLOY M, 1995, RANDOM STRUCT ALGOR, V6, P161 0134 MOREIRA AA, 2002, PHYS REV LETT, V89 0135 NEWMAN MEJ, 2001, PHYS REV E 2, V64 0136 NEWMAN MEJ, 2002, PHYS REV LETT, V89 0137 NEWMAN MEJ, 2003, PHYS REV E 2, V67 0138 NEWMAN MEJ, 2003, SIAM REV, V45, P167 0139 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 0140 PASTORSATORRAS R, 2004, EVOLUTION STRUCTURE 0141 PRICE DJ, 1986, LITTLE SCI BIG SCI 0142 QIAN C, 2002, P IEEE INFOCOM NEW Y, V2, P608 0143 VAZQUEZ A, 2002, PHYS REV E 2, V65 0144 WASSERMAN S, 1994, SOCIAL NETWORK ANAL 0145 ZHOU S, 2004, IEEE COMMUN LETT, V8, P180 0146 NR 28 0147 TC 16 0148 PU NATURE PUBLISHING GROUP 0149 PI LONDON 0150 PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND 0151 SN 1745-2473 0152 J9 NAT PHYS 0153 JI Nat. Phys. 0154 PD FEB 0155 PY 2006 0156 VL 2 0157 IS 2 0158 BP 110 0159 EP 115 0160 PG 6 0161 SC Physics, Multidisciplinary 0162 GA 014FM 0163 UT ISI:000235464700021 0164 ER 0165 0166 PT J 0167 AU Vespignani, A 0168 TI Behind enemy lines 0169 SO NATURE PHYSICS 0170 LA English 0171 DT News Item 0172 ID SPREAD; EPIDEMIOLOGY; COMPUTERS; NETWORKS; VIRUSES 0173 AB Computer viruses can spread through networks with alarming speed. But 0174 there is hope that those fighting the plague can keep up with the pace. 0175 C1 Indiana Univ, Sch Informat, Dept Phys, Bloomington, IN 47406 USA. 0176 Indiana Univ, Ctr Biocomplex, Bloomington, IN 47406 USA. 0177 RP Vespignani, A, Indiana Univ, Sch Informat, Dept Phys, Bloomington, IN 0178 47406 USA. 0179 EM alexv@indiana.edu 0180 CR BALTHROP J, 2004, SCIENCE, V304, P527 0181 GOLDENBERG J, 2005, NAT PHYS, V1, P184 0182 HOFMEYR S, 1999, EVOLUTIONARY COMPUTA, V7, P45 0183 KEPHART JO, 1993, IEEE SPECTRUM, V30, P20 0184 LLOYD AL, 2001, SCIENCE, V292, P1316 0185 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 0186 SHANNON C, 2004, IEEE SECUR PRIV, V2, P46 0187 NR 7 0188 TC 0 0189 PU NATURE PUBLISHING GROUP 0190 PI LONDON 0191 PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND 0192 SN 1745-2473 0193 J9 NAT PHYS 0194 JI Nat. Phys. 0195 PD DEC 0196 PY 2005 0197 VL 1 0198 IS 3 0199 BP 135 0200 EP 136 0201 PG 2 0202 SC Physics, Multidisciplinary 0203 GA 006HK 0204 UT ISI:000234888400009 0205 ER 0206 0207 PT S 0208 AU Dall'Asta, L 0209 Alvarez-Hamelin, I 0210 Barrat, A 0211 Vazquez, A 0212 Vespignani, A 0213 TI Traceroute-like exploration of unknown networks: A statistical analysis 0214 SO COMBINATORIAL AND ALGORITHMIC ASPECTS OF NETWORKING 0215 SE LECTURE NOTES IN COMPUTER SCIENCE 0216 LA English 0217 DT Article 0218 ID BETWEENNESS; CENTRALITY; INTERNET 0219 AB Mapping the Internet generally consists in sampling the network from a 0220 limited set of sources by using traceroute-like probes. This 0221 methodology has been argued to introduce uncontrolled sampling biases 0222 that might produce statistical properties of the sampled graph which 0223 sharply differ from the original ones. Here we explore these biases and 0224 provide a statistical analysis of their origin. We derive a mean-field 0225 analytical approximation for the probability of edge and vertex 0226 detection that allows us to relate the global topological properties of 0227 the underlying network with the statistical accuracy of the sampled 0228 graph. In particular we show that shortest path routed sampling allows 0229 a clear characterization of underlying graphs with scale-free topology. 0230 We complement the analytical discussion with a throughout numerical 0231 investigation of simulated mapping strategies in different network 0232 models. 0233 C1 Univ Paris 11, CNRS, UMR 8627, Phys Theor Lab, F-91405 Orsay, France. 0234 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. 0235 RP Dall'Asta, L, Univ Paris 11, CNRS, UMR 8627, Phys Theor Lab, Batiment 0236 210, F-91405 Orsay, France. 0237 CR BALDI P, 2003, PROBABILSISTIC METHO 0238 BARABASAI AL, 1998, SCIENCE, V286, P509 0239 BARTHELEMY M, 2004, EUR PHYS J B, V38, P163 0240 BRANDES U, 2001, J MATH SOCIOL, V25, P163 0241 BROIDO A, 2001, P SPIE INT S CONV IT 0242 BURCH H, 1999, IEEE COMPUT, V32, P97 0243 CALDARELLI G, 2000, EUROPHYS LETT, V52, P386 0244 CHEN Q, 2002, P IEEE INFOCOM 2002 0245 CLAUSET A, 2003, ARXIVCONDMAT0312674 0246 DOROGOVTSEV SN, 2001, PHYS REV E 1, V63 0247 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 0248 ERDOS P, 1960, PUBL MATH I HUNG, V5, P17 0249 FALOUTSOS M, 1999, ACM SIGCOMM COMPUTER, V29, P251 0250 FREEMAN LC, 1977, SOCIOMETRY, V40, P35 0251 GOH KI, 2001, PHYS REV LETT, V87 0252 GOVINDAN R, 2000, P IEEE INFOCOM, V3, P1371 0253 JIN C, 2000, CSETR43300 EECS DEPT 0254 LAKHINA A, 2002, BUCSTR2002021 BOST U 0255 MEDINA A, 2000, BUCSTR2000005 BOST U 0256 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 0257 PASTORSATORRAS R, 2004, EVOLUTION STRUCTURE 0258 PETERMANN T, 2004, EUR PHYS J B, V38, P201 0259 VAZQUEZ A, 2002, PHYS REV E 2, V65 0260 WATTS DJ, 1998, NATURE, V393, P440 0261 WILLINGER W, 2002, P NATL ACAD SCI U S1, V99, P2573 0262 NR 25 0263 TC 2 0264 PU SPRINGER-VERLAG BERLIN 0265 PI BERLIN 0266 PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY 0267 SN 0302-9743 0268 J9 LECT NOTE COMPUT SCI 0269 PY 2005 0270 VL 3405 0271 BP 140 0272 EP 153 0273 PG 14 0274 SC Computer Science, Theory & Methods 0275 GA BCT65 0276 UT ISI:000231145300013 0277 ER 0278 0279 PT J 0280 AU Vergassola, M 0281 Vespignani, A 0282 Dujon, B 0283 TI Cooperative evolution in protein complexes of yeast from comparative 0284 analyses of its interaction network 0285 SO PROTEOMICS 0286 LA English 0287 DT Article 0288 DE comparative analyses; evolution; protein-protein interaction networks; 0289 Saccharomyces cerevisiae 0290 ID SACCHAROMYCES-CEREVISIAE; SIMPLE DEPENDENCE; DATA SETS; NUMBER; 0291 GENERATION 0292 AB A comparative analysis among Saccharomyces cerevisiae and the other 0293 four yeasts Candida glabrata, Kluyveromyces lactis, Debaryomyces 0294 hansenii, and Yarrowia lipolytica is presented. The broad evolutionary 0295 range spanned by the organisms allows to quantitatively demonstrate 0296 novel evolutionary effects in protein complexes. The evolution rates 0297 within cliques of interlinked proteins are found to bear strong 0298 multipoint correlations, witnessing a cooperative coevolution of 0299 complex subunits. The coevolution is found to be largely independent of 0300 the tendency of the subunits to have similar abundances. 0301 C1 Inst Pasteur, Dept Struct & Dynam Genomes, Unite Genom Microorganismes Pathogenes, CNRS URA 2171, F-757724 Paris, France. 0302 Univ Paris 11, Phys Theor Lab, CNRS, UMR 8627, Orsay, France. 0303 Univ Paris 06, Inst Pasteur, Unite Genet Mol Levures, UFR 927, Paris, France. 0304 Univ Paris 06, Inst Pasteur, Unite Genet Mol Levures, CNRS URA 2171, Paris, France. 0305 RP Vergassola, M, Inst Pasteur, Dept Struct & Dynam Genomes, Unite Genom 0306 Microorganismes Pathogenes, CNRS URA 2171, 28 Rue Dr Roux, F-757724 0307 Paris, France. 0308 EM massimo@pasteur.fr 0309 CR ALBERTS B, 1998, CELL, V92, P291 0310 ALTSCHUL SF, 1997, NUCLEIC ACIDS RES, V25, P3389 0311 BLOOM JD, 2003, BMC EVOL BIOL, V3 0312 DUJON B, 2004, NATURE, V430, P35 0313 FRASER HB, 2002, SCIENCE, V296, P750 0314 FRASER HB, 2003, BMC EVOL BIOL, V3 0315 GAVIN AC, 2002, NATURE, V415, P141 0316 GHAEMMAGHAMI S, 2003, NATURE, V425, P737 0317 GOH CS, 2000, J MOL BIOL, V299, P283 0318 HARTWELL LH, 1999, NATURE, V402, P47 0319 HO Y, 2002, NATURE, V415, P180 0320 ITO T, 2001, P NATL ACAD SCI USA, V98, P4569 0321 JEONG H, 2001, NATURE, V411, P41 0322 JORDAN IK, 2003, BMC EVOL BIOL, V3 0323 MILO R, 2002, SCIENCE, V298, P824 0324 PAL C, 2001, GENETICS, V158, P927 0325 PAZOS F, 2002, PROTEINS, V47, P219 0326 PELLEGRINI M, 1999, P NATL ACAD SCI USA, V96, P4285 0327 UETZ P, 2000, NATURE, V403, P623 0328 VALENCIA A, 2002, CURR OPIN STRUC BIOL, V12, P368 0329 VONMERING C, 2002, NATURE, V417, P399 0330 WILCOXON F, 1945, BIOMETRICS, V1, P80 0331 WUCHTY S, 2003, NAT GENET, V35, P176 0332 NR 23 0333 TC 2 0334 PU WILEY-V C H VERLAG GMBH 0335 PI WEINHEIM 0336 PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY 0337 SN 1615-9853 0338 J9 PROTEOMICS 0339 JI Proteomics 0340 PD AUG 0341 PY 2005 0342 VL 5 0343 IS 12 0344 BP 3116 0345 EP 3119 0346 PG 4 0347 SC Biochemical Research Methods; Biochemistry & Molecular Biology 0348 GA 956QW 0349 UT ISI:000231315900015 0350 ER 0351 0352 PT J 0353 AU Barrat, A 0354 Barthelemy, M 0355 Vespignani, A 0356 TI The effects of spatial constraints on the evolution of weighted complex 0357 networks 0358 SO JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT 0359 LA English 0360 DT Article 0361 DE network dynamics; random graphs; networks 0362 ID SMALL-WORLD NETWORKS; SCALE-FREE; RANDOM GRAPHS; TOPOLOGY 0363 AB Motivated by the empirical analysis of the air transportation system, 0364 we de. ne a network model that includes geographical attributes along 0365 with topological and weight (traffic) properties. The introduction of 0366 geographical attributes is made by constraining the network in real 0367 space. Interestingly, the inclusion of geometrical features induces 0368 non-trivial correlations between the weights, the connectivity pattern 0369 and the actual spatial distances of vertices. The model also recovers 0370 the emergence of anomalous fluctuations in the betweenness-degree 0371 correlation function as first observed by Guimera a and Amaral (2004 0372 Eur. Phys. J. B 38 381). The presented results suggest that the 0373 interplay between weight dynamics and spatial constraints is a key 0374 ingredient in order to understand the formation of real-world weighted 0375 networks. 0376 C1 Univ Paris 11, Phys Theor Lab, CNRS, UMR 8627, F-91405 Orsay, France. 0377 Indiana Univ, Sch Informat, Bloomington, IN 47406 USA. 0378 Indiana Univ, Biocomplex Ctr, Bloomington, IN 47406 USA. 0379 RP Barrat, A, Univ Paris 11, Phys Theor Lab, CNRS, UMR 8627, Batiment 210, 0380 F-91405 Orsay, France. 0381 EM Alain.Barrat@th.u-psud.fr 0382 mbarthel@indiana.edu 0383 alexv@indiana.edu 0384 CR ALBERT R, 2000, NATURE, V406, P378 0385 ALBERT R, 2002, REV MOD PHYS, V74, P47 0386 ALMAAS E, 2004, NATURE, V427, P839 0387 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 0388 ANTAL T, 2004, CONDMAT0408285 0389 BARABASI AL, 1999, SCIENCE, V286, P509 0390 BARRAT A, 2004, LECT NOTES COMPUT SC, V3243, P56 0391 BARRAT A, 2004, P NATL ACAD SCI USA, V101, P3747 0392 BARRAT A, 2004, PHYS REV E 2, V70 0393 BARRAT A, 2004, PHYS REV LETT, V92 0394 BARRAT A, 2005, PHYS REV E 2, V71 0395 BARTHELEMY M, 2003, EUR PHYS J B, V38, P163 0396 BARTHELEMY M, 2003, EUROPHYS LETT, V63, P915 0397 BIANCONI G, CONDMAT0412399 0398 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 0399 COHEN R, 2000, PHYS REV LETT, V85, P4626 0400 DOROGOVTSEV SN, 2002, ADV PHYS, V51, P1079 0401 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 0402 DOROGOVTSEV SN, 2004, CONDMAT0408343 0403 FREEMAN LC, 1977, SOCIOMETRY, V40, P35 0404 GARLASCHELLI D, 2005, PHYSICA A, V350, P491 0405 GASTNER MT, 2004, CONDMAT0407680 0406 GASTNER MT, 2004, CONDMAT0409702 0407 GOH KI, 2001, PHYS REV LETT, V87 0408 GORMAN SP, 2003, UNPUB ENV PLANNING B 0409 GRANOVET.MS, 1973, AM J SOCIOL, V78, P1360 0410 GUIMERA R, 2003, CONDMAT0312535 0411 GUIMERA R, 2004, EUR PHYS J B, V38, P381 0412 HELMY A, 2002, CSNI0207069 0413 KRAUSE AE, 2003, NATURE, V426, P282 0414 LAKHINA A, TECHNICAL REPORT 0415 LI C, 2003, CONDMAT0311333 0416 LI W, 2004, PHYS REV E 2, V69 0417 MANNA SS, 2002, PHYS REV E 2, V66 0418 MASUDA N, 2005, PHYS REV E 2, V71 0419 MOLLOY M, 1995, RANDOM STRUCT ALGOR, V6, P161 0420 MUKHERJEE G, 2005, CONDMAT0503697 0421 NEMETH G, 2003, PHYS REV E 2, V67 0422 NEWMAN MEJ, 2001, PHYS REV E 2, V64 0423 NEWMAN MEJ, 2001, PHYS REV E 2, V64 0424 NEWMAN MEJ, 2002, PHYS REV LETT, V89 0425 ONNELA JP, 2004, CONDMAT0408629 0426 PANDYA RVR, 2004, CONDMAT0406644 0427 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 0428 PASTORSATORRAS R, 2004, EVOLUTION STRUCTURE 0429 VAZQUEZ A, 2002, PHYS REV E 2, V65 0430 WANG WX, 2005, CONDMAT0501215 0431 WATTS DJ, 1998, NATURE, V393, P440 0432 WAXMAN BM, 1988, IEEE J SEL AREA COMM, V6, P1617 0433 XULVIBRUNET R, 2002, PHYS REV E 2, V66 0434 YOOK SH, 2001, PHYS REV LETT, V86, P5835 0435 YOOK SH, 2002, P NATL ACAD SCI USA, V99, P13382 0436 NR 52 0437 TC 3 0438 PU IOP PUBLISHING LTD 0439 PI BRISTOL 0440 PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND 0441 SN 1742-5468 0442 J9 J STAT MECH-THEORY EXP 0443 JI J. Stat. Mech.-Theory Exp. 0444 PD MAY 0445 PY 2005 0446 AR P05003 0447 DI ARTN P05003 0448 PG 20 0449 SC Mechanics; Physics, Mathematical 0450 GA 932WW 0451 UT ISI:000229586200013 0452 ER 0453 0454 PT J 0455 AU Dall'Asta, L 0456 Alvarez-Hamelin, I 0457 Barrat, A 0458 Vazquez, A 0459 Vespignani, A 0460 TI Statistical theory of Internet exploration 0461 SO PHYSICAL REVIEW E 0462 LA English 0463 DT Article 0464 ID COMPLEX NETWORKS; BETWEENNESS; CENTRALITY 0465 AB The general methodology used to construct Internet maps consists in 0466 merging all the discovered paths obtained by sending data packets from 0467 a set of active computers to a set of destination hosts, obtaining a 0468 graphlike representation of the network. This technique, sometimes 0469 referred to as Internet tomography, spurs the issue concerning the 0470 statistical reliability of such empirical maps. We tackle this problem 0471 by modeling the network sampling process on synthetic graphs and by 0472 using a mean-field approximation to obtain expressions for the 0473 probability of edge and vertex detection in the sampled graph. This 0474 allows a general understanding of the origin of possible sampling 0475 biases. In particular, we find a direct dependence of the map 0476 statistical accuracy upon the topological properties (in particular, 0477 the betweenness centrality property) of the underlying network. In this 0478 framework, it appears that statistically heterogeneous network 0479 topologies are captured better than the homogeneous ones during the 0480 mapping process. Finally, the analytical discussion is complemented 0481 with a thorough numerical investigation of simulated mapping strategies 0482 in network models with varying topological properties. 0483 C1 Univ Paris 11, Phys Theor Lab, F-91405 Orsay, France. 0484 Univ Buenos Aires, Fac Ingn, RA-1063 Buenos Aires, DF, Argentina. 0485 Univ Notre Dame, Notre Dame, IN 46556 USA. 0486 Indiana Univ, Sch Informat, Bloomington, IN 47408 USA. 0487 Indiana Univ, Dept Phys, Bloomington, IN 47408 USA. 0488 RP Dall'Asta, L, Univ Paris 11, Phys Theor Lab, Batiment 210, F-91405 0489 Orsay, France. 0490 CR ALBERT R, 2002, REV MOD PHYS, V74, P47 0491 BALDI P, 2003, MODELING INTERNET WE 0492 BARABASI AL, 1999, SCIENCE, V286, P509 0493 BARTHELEMY M, 2004, EUR PHYS J B, V38, P163 0494 BRANDES U, 2001, J MATH SOCIOL, V25, P163 0495 BROIDO A, 2001, SAN DIEG P SPIE INT 0496 BURCH H, 1999, IEEE COMPUT, V32, P97 0497 CALDARELLI G, 2000, EUROPHYS LETT, V52, P386 0498 CHEN Q, 2002, P IEEE INFOCOM 2002 0499 CLAUSET A, 2005, PHYS REV LETT, V94 0500 DOROGOVTSEV SN, 2001, PHYS REV E 1, V63 0501 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 0502 ERDOS P, 1959, PUBL MATH-DEBRECEN, V6, P290 0503 FALOUTSOS M, 1999, COMP COMM R, V29, P251 0504 FREEMAN LC, 1977, SOCIOMETRY, V40, P35 0505 GOH KI, 2001, PHYS REV LETT, V87 0506 GOVINDAN R, 2000, P IEEE INFOCOM TEL A, P1371 0507 GUILLAUME JL, 2005, IN PRESS P IEEE INFO 0508 JIN C, 2000, CSETR43300 EECS DEP 0509 LAKHINA A, 2002, BUCSTR2002021 DEP CO 0510 MEDINA A, 2000, BUCSTR2000005 0511 NEWMAN MEJ, 2002, PHYS REV LETT, V89 0512 NEWMAN MEJ, 2003, SIAM REV, V45, P167 0513 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 0514 PASTORSATORRAS R, 2004, EVOLUTION STRUCTURE 0515 PETERMANN T, 2004, EUR PHYS J B, V38, P201 0516 VAZQUEZ A, 2002, PHYS REV E 2, V65 0517 WATTS DJ, 1998, NATURE, V393, P440 0518 WILLINGER W, 2002, P NATL ACAD SCI U S1, V99, P2573 0519 NR 29 0520 TC 6 0521 PU AMERICAN PHYSICAL SOC 0522 PI COLLEGE PK 0523 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 0524 SN 1063-651X 0525 J9 PHYS REV E 0526 JI Phys. Rev. E 0527 PD MAR 0528 PY 2005 0529 VL 71 0530 IS 3 0531 PN Part 2 0532 AR 036135 0533 DI ARTN 036135 0534 PG 9 0535 SC Physics, Fluids & Plasmas; Physics, Mathematical 0536 GA 922EC 0537 UT ISI:000228818200045 0538 ER 0539 0540 PT J 0541 AU Colizza, V 0542 Flammini, A 0543 Maritan, A 0544 Vespignani, A 0545 TI Characterization and modeling of protein-protein interaction networks 0546 SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS 0547 LA English 0548 DT Article 0549 DE protein interaction networks; complex networks; evolution modeling 0550 ID GROWING RANDOM NETWORKS; SACCHAROMYCES-CEREVISIAE; COMPLEX NETWORKS; 0551 YEAST GENOME; FUNCTIONAL-ORGANIZATION; STATISTICAL-MECHANICS; METABOLIC 0552 NETWORKS; EVOLVING NETWORKS; SIMPLE DEPENDENCE; EVOLUTIONARY RATE 0553 AB The recent availability of high-throughput gene expression and 0554 proteomics techniques has created an unprecedented opportunity for a 0555 comprehensive study of the structure and dynamics of many biological 0556 networks. Global proteomic interaction data, in particular, are 0557 synthetically represented as undirected networks exhibiting features 0558 far from the random paradigm which has dominated past effort in network 0559 theory. This evidence, along with the advances in the theory of complex 0560 networks, has triggered an intense research activity aimed at 0561 exploiting the evolutionary and biological significance of the 0562 resulting network's topology. Here we present a review of the results 0563 obtained in the characterization and modeling of the yeast 0564 Saccharomyces Cerevisiae protein interaction networks obtained with 0565 different experimental techniques. We provide a comparative assessment 0566 of the topological properties and discuss possible biases in 0567 interaction networks obtained with different techniques. We report on 0568 dynamical models based on duplication mechanisms that cast the protein 0569 interaction networks in the family of dynamically growing complex 0570 networks. Finally, we discuss various results and analysis correlating 0571 the networks' topology with the biological function of proteins. (c) 0572 2005 Published by Elsevier B.V. 0573 C1 Indiana Univ, Sch Informat & Biocomplex Ctr, Bloomington, IN 47408 USA. 0574 Univ Padua, INFM, I-35131 Padua, Italy. 0575 Univ Padua, Dept Phys, I-35131 Padua, Italy. 0576 RP Vespignani, A, Indiana Univ, Sch Informat & Biocomplex Ctr, 0577 Bloomington, IN 47408 USA. 0578 EM alessandro.vespignani@th.u-psud.fr 0579 CR ALBERT R, 2002, REV MOD PHYS, V74, P47 0580 ALON U, 2003, SCIENCE, V301, P1866 0581 BADER GD, 2002, NAT BIOTECHNOL, V20, P991 0582 BARABASI AL, 1999, PHYSICA A, V272, P173 0583 BARABASI AL, 1999, SCIENCE, V286, P509 0584 BARABASI AL, 2004, NAT REV GENET, V5, P101 0585 BHAN A, 2002, BIOINFORMATICS, V18, P1486 0586 BIANCONI G, 2001, EUROPHYS LETT, V54, P436 0587 BIANCONI G, 2001, PHYS REV LETT, V86, P5632 0588 BIANCONI G, 2003, PHYS REV LETT, V90 0589 BLOOM JD, 2003, BMC EVOL BIOL, V3 0590 BOLLOBAS B, 2001, RANDOM GRAPHS 0591 BRODER A, 2000, COMPUT NETW, V33, P309 0592 BRUN C, 2003, GENOME BIOL, V5, R6 0593 CHO RJ, 1998, MOL 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V294, P2364 0660 UETZ P, 2000, NATURE, V403, P623 0661 VALENCIA A, 2002, CURR OPIN STRUC BIOL, V12, P368 0662 VAZQUEZ A, 2002, PHYS REV E 2, V65 0663 VAZQUEZ A, 2003, COMPLEXUS, V1, P38 0664 VAZQUEZ A, 2003, NAT BIOTECHNOL, V21, P697 0665 VAZQUEZ A, 2003, PHYS REV E 2, V67 0666 VONMERING C, 2002, NATURE, V417, P399 0667 WAGNER A, 2001, MOL BIOL EVOL, V18, P1283 0668 WAGNER A, 2001, P ROY SOC LOND B BIO, V268, P1803 0669 WAGNER A, 2003, P ROY SOC LOND B BIO, V270, P457 0670 WATTS DJ, 1998, NATURE, V393, P440 0671 WOLF YI, 2002, BIOESSAYS, V24, P105 0672 WOLFE KH, 1997, NATURE, V387, P708 0673 WUCHTY S, 2003, NAT GENET, V35, P176 0674 XENARIOS I, 2001, CURR OPIN BIOTECH, V12, P334 0675 YOOK SH, 2004, PROTEOMICS, V4, P928 0676 ZHANG MQ, 1999, COMPUT CHEM, V23, P233 0677 NR 98 0678 TC 7 0679 PU ELSEVIER SCIENCE BV 0680 PI AMSTERDAM 0681 PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS 0682 SN 0378-4371 0683 J9 PHYSICA A 0684 JI Physica A 0685 PD JUL 1 0686 PY 2005 0687 VL 352 0688 IS 1 0689 BP 1 0690 EP 27 0691 PG 27 0692 SC Physics, Multidisciplinary 0693 GA 927KR 0694 UT ISI:000229193300002 0695 ER 0696 0697 PT J 0698 AU Barthelemy, M 0699 Barrat, A 0700 Pastor-Satorras, R 0701 Vespignani, A 0702 TI Dynamical patterns of epidemic outbreaks in complex heterogeneous 0703 networks 0704 SO JOURNAL OF THEORETICAL BIOLOGY 0705 LA English 0706 DT Article 0707 DE complex networks; disease spreading; epidemic modeling 0708 ID SCALE-FREE NETWORKS; SEXUAL CONTACTS; TRANSMISSION 0709 AB We present a thorough inspection of the dynamical behavior of epidemic 0710 phenomena in populations with complex and heterogeneous connectivity 0711 patterns. We show that the growth of the epidemic prevalence is 0712 virtually instantaneous in all networks characterized by diverging 0713 degree fluctuations, independently of the structure of the connectivity 0714 correlation functions characterizing the population network. By means 0715 of analytical and numerical results, we show that the outbreak time 0716 evolution follows a precise hierarchical dynamics. Once reached the 0717 most highly connected hubs, the infection pervades the network in a 0718 progressive cascade across smaller degree classes. Finally, we show the 0719 influence of the initial conditions and the relevance of statistical 0720 results in single case studies concerning heterogeneous networks. The 0721 emerging theoretical framework appears of general interest in view of 0722 the recently observed abundance of natural networks with complex 0723 topological features and might provide useful insights for the 0724 development of adaptive strategies aimed at epidemic containment. (c) 0725 2005 Elsevier Ltd. All rights reserved. 0726 C1 Ctr Etud Bruyeres Le Chatel, CEA, Dept Phys Theor & Appl, F-91680 Bruyeres Le Chatel, France. 0727 Univ Paris 11, UMR 8627, CNRS, Phys Theor Lab, F-91405 Orsay, France. 0728 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 0729 Indiana Univ, Sch Informat, Bloomington, IN 47408 USA. 0730 Indiana Univ, Biocomplex Ctr, Bloomington, IN 47408 USA. 0731 RP Barthelemy, M, Ctr Etud Bruyeres Le Chatel, CEA, Dept Phys Theor & 0732 Appl, BP 12, F-91680 Bruyeres Le Chatel, France. 0733 EM marc.barthelemy@th.u-psud.fr 0734 CR ALBERT R, 2002, REV MOD PHYS, V74, P47 0735 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 0736 ANDERSON RM, 1992, INFECT DIS HUMANS 0737 BAILEY NTJ, 1975, MATH THEORY INFECT D 0738 BARABASI AL, 1999, SCIENCE, V286, P509 0739 BARRAT A, 2004, P NATL ACAD SCI USA, V101, P3747 0740 BARTHELEMY M, 2002, PHYSICA A, V319, P633 0741 BARTHELEMY M, 2004, PHYS REV LETT, V92 0742 BOGUNA M, 2002, PHYS REV E 2, V66 0743 BOGUNA M, 2003, LECT NOTES PHYS, V625 0744 BOGUNA M, 2003, PHYS REV LETT, V90 0745 BOLLOBAS B, 1985, RANDOM GRAPHS 0746 COHEN R, 2003, PHYS REV LETT, V90 0747 COLGATE SA, 1989, P NATL ACAD SCI USA, V86, P4793 0748 DAILEY DJ, 2001, EPIDEMIC MODELLING I 0749 DERRIDA B, 1987, J PHYS A-MATH GEN, V20, P5273 0750 DEZSO Z, 2002, PHYS REV E 2, V65 0751 DIEKMANN O, 2000, MATH EPIDEMIOLOGY IN 0752 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 0753 ERDOS P, 1959, PUBL MATH-DEBRECEN, V6, P290 0754 EUBANK S, 2004, NATURE, V429, P180 0755 FERGUSON NM, 2003, NATURE, V425, P681 0756 GANTMACHER FR, 1974, THEORY MATRICES, V2 0757 GUIMERA R, 2003, CONDMAT0312535 0758 HETHCOTE HW, 1984, LECT NOTES BIOMATHS, V56, P1 0759 LILJEROS F, 2001, NATURE, V411, P907 0760 LLOYD AL, 2001, SCIENCE, V292, P1316 0761 MAY RM, 1984, MATH BIOSCI, V72, P83 0762 MAY RM, 1988, PHIL T R SOC LOND B, V321, P565 0763 MAY RM, 2001, PHYS REV E 2, V64 0764 MORENO Y, 2002, EUR PHYS J B, V26, P521 0765 MORENO Y, 2003, EUR PHYS J B, V31, P265 0766 MURRAY JD, 1993, MATH BIOL 0767 NEWMAN MEJ, 2002, PHYS REV E 2, V66 0768 NEWMAN MEJ, 2002, PHYS REV LETT, V89 0769 PASTORSATORRAS R, 2001, PHYS REV E 2, V63 0770 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 0771 SCHNEEBERGER A, 2004, SEX TRANSM DIS, V31, P380 0772 YORKE JA, 1978, SEX TRANSM DIS, V5, P51 0773 NR 39 0774 TC 33 0775 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD 0776 PI LONDON 0777 PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND 0778 SN 0022-5193 0779 J9 J THEOR BIOL 0780 JI J. Theor. Biol. 0781 PD JUL 21 0782 PY 2005 0783 VL 235 0784 IS 2 0785 BP 275 0786 EP 288 0787 PG 14 0788 SC Biology; Mathematical & Computational Biology 0789 GA 928BQ 0790 UT ISI:000229246500011 0791 ER 0792 0793 PT J 0794 AU Borner, K 0795 Dall'Asta, L 0796 Ke, WM 0797 Vespignani, A 0798 TI Studying the emerging global brain: Analyzing and visualizing the 0799 impact of co-authorship teams 0800 SO COMPLEXITY 0801 LA English 0802 DT Article 0803 DE weighted network analysis; co-author networks; citation analysis; 0804 information visualization 0805 ID NETWORKS 0806 AB This article introduces a suite of approaches and measures to study the 0807 impact of co-authorship teams based on the number of publications and 0808 their citations on a local and global scale. In particular, we present 0809 a novel weighted graph representation that encodes coupled author-paper 0810 networks as a weighted co-authorship graph. This weighted graph 0811 representation is applied to a dataset that captures the emergence of a 0812 new field of science and comprises 614 articles published by 1036 0813 unique authors between 1974 and 2004. To characterize the properties 0814 and evolution of this field, we first use four different measures of 0815 centrality to identify the impact of authors. A global statistical 0816 analysis is performed to characterize the distribution of paper 0817 production and paper citations and its correlation with the 0818 co-authorship team size. The size of co-authorship clusters over time 0819 is examined. Finally, a novel local, author-centered measure based on 0820 entropy is applied to determine the global evolution of the field and 0821 the identification of the contribution of a single author's impact 0822 across all of its co-authorship relations. A visualization of the 0823 growth of the weighted co-author network, and the results obtained from 0824 the statistical analysis indicate a drift toward a more cooperative, 0825 global collaboration process as the main drive in the production of 0826 scientific knowledge. (c) 2005 Wiley Periodicals, Inc. 0827 C1 Indiana Univ, SLIS, Bloomington, IN 47405 USA. 0828 Univ Paris 11, Phys Theor Lab, F-91405 Orsay, France. 0829 Indiana Univ, Sch Informat, Bloomington, IN 47406 USA. 0830 Indiana Univ, Biocomplex Ctr, Bloomington, IN 47406 USA. 0831 RP Borner, K, Indiana Univ, SLIS, Bloomington, IN 47405 USA. 0832 EM katy@indiana.edu 0833 CR ALMAAS E, 2004, NATURE, P427 0834 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 0835 BARABASI AL, 1999, SCIENCE, V286, P509 0836 BARABASI AL, 2002, LINKED 0837 BARRAT A, 2004, P NATL ACAD SCI USA, V101, P3747 0838 BATAGELJ V, 1998, CONNECTIONS, V21, P47 0839 BEAVER DD, 1978, SCIENTOMETRICS, V1, P65 0840 BLOOM H, 2000, GLOBAL BRAIN EVOLUTI 0841 BORNER K, 2003, VISUALIZING KNOWLEDG, P179 0842 BORNER K, 2004, P NATL ACAD SCI U S1, V101, P5266 0843 CRANE D, 1972, INVISIBLE COLL DIFFU 0844 CRONIN B, 1994, J AM SOC INFORM SCI, V45, P61 0845 DOROGOVSTEV SN, 2003, EVOLUTION NETWORKS 0846 FREEMAN LC, 1977, SOCIOMETRY, V40, P35 0847 GUIMERA R, 2004, TEAM ASSEMBLY MECH D 0848 KAMADA T, 1989, INFORM PROCESS LETT, V31, P7 0849 NEWMAN MEJ, 2001, PHYS REV E 2, V64 0850 NEWMAN MEJ, 2001, PHYS REV E 2, V64 0851 NEWMAN MEJ, 2004, P NATL ACAD SCI U S1, V101, P5200 0852 NEWMAN MEJ, 2004, PHYS REV E 2, V70 0853 PASTORSATORRAS R, 2004, EVOLUTION STRUCTURE 0854 RAMASCO JJ, 2004, PHYS REV E 2, V70 0855 WASSERMAN S, 1994, METHODS APPL STRUCTU, V8 0856 WHITE HD, 2001, SCIENTOMETRICS, V51, P607 0857 NR 24 0858 TC 2 0859 PU JOHN WILEY & SONS INC 0860 PI HOBOKEN 0861 PA 111 RIVER ST, HOBOKEN, NJ 07030 USA 0862 SN 1076-2787 0863 J9 COMPLEXITY 0864 JI Complexity 0865 PD MAR-APR 0866 PY 2005 0867 VL 10 0868 IS 4 0869 BP 57 0870 EP 67 0871 PG 11 0872 SC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences 0873 GA 917NJ 0874 UT ISI:000228469000006 0875 ER 0876 0877 PT J 0878 AU Barrat, A 0879 Barthelemy, M 0880 Vespignani, A 0881 TI Modeling the evolution of weighted networks 0882 SO PHYSICAL REVIEW E 0883 LA English 0884 DT Article 0885 ID SMALL-WORLD NETWORKS; SCALE-FREE NETWORKS; EVOLVING NETWORKS; COMPLEX 0886 NETWORKS 0887 AB We present a general model for the growth of weighted networks in which 0888 the structural growth is coupled with the edges' weight dynamical 0889 evolution. The model is based on a simple weight-driven dynamics and a 0890 weights' reinforcement mechanism coupled to the local network growth. 0891 That coupling can be generalized in order to include the effect of 0892 additional randomness and nonlinearities which can be present in 0893 real-world networks. The model generates weighted graphs exhibiting the 0894 statistical properties observed in several real-world systems. In 0895 particular, the model yields a nontrivial time evolution of vertices' 0896 properties and scale-free behavior with exponents depending on the 0897 microscopic parameters characterizing the coupling rules. Very 0898 interestingly, the generated graphs spontaneously achieve a complex 0899 hierarchical architecture characterized by clustering and connectivity 0900 correlations varying as a function of the vertices' degree. 0901 C1 Univ Paris 11, Phys Theor Lab, CNRS, UMR 8627, F-91405 Orsay, France. 0902 Ctr Etud Bruyeres Le Chatel, CEA, Dept Phys Theor & Appl, F-91680 Bruyeres Le Chatel, France. 0903 Indiana Univ, Sch Informat, Bloomington, IN 47408 USA. 0904 RP Barrat, A, Univ Paris 11, Phys Theor Lab, CNRS, UMR 8627, Batiment 210, 0905 F-91405 Orsay, France. 0906 CR ALBERT R, 2000, NATURE, V406, P378 0907 ALBERT R, 2002, REV MOD PHYS, V74, P47 0908 ALMAAS E, 2004, NATURE, V427, P839 0909 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 0910 BARABASI AL, 1999, SCIENCE, V286, P509 0911 BARABASI AL, 2002, PHYSICA A, V311, P590 0912 BARRAT A, UNPUB 0913 BARRAT A, 2004, LECT NOTES COMPUT SC, V3243, P56 0914 BARRAT A, 2004, P NATL ACAD SCI USA, V101, P3747 0915 BARRAT A, 2004, PHYS REV LETT, V92 0916 BARTHELEMY M, UNPUB 0917 BIANCONI G, 2001, EUROPHYS LETT, V54, P436 0918 CALDARELLI G, 2002, PHYS REV LETT, V89 0919 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 0920 COHEN R, 2000, PHYS REV LETT, V85, P4626 0921 DOROGOVTSEV SN, 2002, ADV PHYS, V51, P1079 0922 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 0923 GARLASCHELLI D, CONDMAT0310503 0924 GRANOVET.MS, 1973, AM J SOCIOL, V78, P1360 0925 GUIMERA R, CONDMAT0312535 0926 KRAUSE AE, 2003, NATURE, V426, P282 0927 LI C, CONDMAT0311333 0928 LI W, 2004, PHYS REV E 2, V69 0929 MASLOV S, 2002, SCIENCE, V296, P910 0930 NEWMAN MEJ, 2001, PHYS REV E 2, V64 0931 NEWMAN MEJ, 2001, PHYS REV E 2, V64 0932 NEWMAN MEJ, 2002, PHYS REV LETT, V89 0933 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 0934 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 0935 PASTORSATORRAS R, 2004, EVOLUTION STRUCTURE 0936 PIMM SL, 2002, FOOD WEBS 0937 RAVASZ E, 2003, PHYS REV E 2, V67 0938 VAZQUEZ A, 2002, PHYS REV E 2, V65 0939 WATTS DJ, 1998, NATURE, V393, P440 0940 YOOK SH, 2001, PHYS REV LETT, V86, P5835 0941 ZHENG DF, 2003, PHYS REV E 1, V67 0942 NR 36 0943 TC 42 0944 PU AMERICAN PHYSICAL SOC 0945 PI COLLEGE PK 0946 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 0947 SN 1063-651X 0948 J9 PHYS REV E 0949 JI Phys. Rev. E 0950 PD DEC 0951 PY 2004 0952 VL 70 0953 IS 6 0954 PN Part 2 0955 AR 066149 0956 DI ARTN 066149 0957 PG 12 0958 SC Physics, Fluids & Plasmas; Physics, Mathematical 0959 GA 887IM 0960 UT ISI:000226299200056 0961 ER 0962 0963 PT J 0964 AU Barthelemy, M 0965 Barrat, A 0966 Pastor-Satorras, R 0967 Vespignani, A 0968 TI Characterization and modeling of weighted networks 0969 SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS 0970 LA English 0971 DT Article 0972 DE disordered system; networks 0973 ID SMALL-WORLD NETWORKS 0974 AB We review the main tools which allow for the statistical 0975 characterization of weighted networks. We then present two case 0976 studies, the airline connection network and the scientific 0977 collaboration network which are representatives of critical 0978 infrastructure and social system, respectively. The main empirical 0979 results are (i) the broad distributions of various quantities and (ii) 0980 the existence of weight-topology correlations. These measurements show 0981 that weights are relevant and that in general the modeling of complex 0982 networks must go beyond topology. We review a model which provides an 0983 explanation for the features observed in several real-world networks. 0984 This model of weighted network formation relies on the dynamical 0985 coupling between topology and weights, considering the rearrangement of 0986 new links are introduced in the system. (C) 2004 Published by Elsevier 0987 B.V. 0988 C1 Ctr Etud Bruyeres Le Chatel, Dept Phys Theor & Appl, CEA, F-91680 Bruyeres Le Chatel, France. 0989 Univ Paris 11, CNRS, UMR 8627, Phys Theor Lab, F-91405 Orsay, France. 0990 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 0991 RP Barthelemy, M, Ctr Etud Bruyeres Le Chatel, Dept Phys Theor & Appl, 0992 CEA, BP 12, F-91680 Bruyeres Le Chatel, France. 0993 EM Marc.Barthelemy@th.u-psud.fr 0994 CR ALBERT R, 2002, REV MOD PHYS, V74, P47 0995 ALMAAS E, 2004, NATURE, V427, P839 0996 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 0997 ANTAL T, CONDMAT0408285 0998 BARABASI AL, 1999, SCIENCE, V286, P509 0999 BARABASI AL, 2002, PHYSICA A, V311, P590 1000 BARRAT A, 2004, CONDMAT0406238 1001 BARRAT A, 2004, CSNI0405070 1002 BARRAT A, 2004, P NATL ACAD SCI USA, V101, P3747 1003 BARRAT A, 2004, PHYS REV LETT, V92 1004 BARTHELEMY M, 2003, PHYSICA A, V319, P633 1005 BARTHELEMY M, 2004, UNPUB 1006 DERRIDA B, 1987, J PHYS A-MATH GEN, V20, P5273 1007 DOROGOVTSEV SN, CONDMAT0408343 1008 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 1009 GARLASCHELLI D, 2003, CONDMAT0310503 1010 GRANOVET.MS, 1973, AM J SOCIOL, V78, P1360 1011 GUIMERA R, 2004, EUR PHYS J B, V38, P381 1012 HU B, 2004, CONDMAT0408125 1013 KRAUSE AE, 2003, NATURE, V426, P282 1014 LI C, 2003, CONDMAT0311333 1015 LI W, 2004, PHYS REV E 2, V69 1016 NEWMAN MEJ, 2001, PHYS REV E 2, V64 1017 NEWMAN MEJ, 2001, PHYS REV E 2, V64 1018 NEWMAN MEJ, 2002, PHYS REV LETT, V89 1019 ONNELA JP, 2003, PHYS REV E 2, V68 1020 PANDYA RVR, 2004, CONDMAT0406644 1021 PASTORSATORRAS R, 2004, EVOLUTION STRUCTURE 1022 WATTS DJ, 1998, NATURE, V393, P440 1023 YOOK SH, 2001, PHYS REV LETT, V86, P5835 1024 ZHENG DF, 2003, PHYS REV E 1, V67 1025 ZHOU S, 2003, CSNI0303028 1026 NR 32 1027 TC 15 1028 PU ELSEVIER SCIENCE BV 1029 PI AMSTERDAM 1030 PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS 1031 SN 0378-4371 1032 J9 PHYSICA A 1033 JI Physica A 1034 PD FEB 1 1035 PY 2005 1036 VL 346 1037 IS 1-2 1038 BP 34 1039 EP 43 1040 PG 10 1041 SC Physics, Multidisciplinary 1042 GA 878YA 1043 UT ISI:000225682200006 1044 ER 1045 1046 PT S 1047 AU Barrat, A 1048 Barthelemy, M 1049 Vespignani, A 1050 TI Traffic-driven model of the World Wide Web graph 1051 SO ALGORITHMS AND MODELS FOR THE WEB-GRAPHS, PROCEEDINGS 1052 SE LECTURE NOTES IN COMPUTER SCIENCE 1053 LA English 1054 DT Article 1055 ID EVOLVING NETWORKS; DYNAMICS 1056 AB We propose a model for the World Wide Web graph that couples the 1057 topological growth with the traffic's dynamical evolution. The model is 1058 based on a simple traffic-driven dynamics and generates weighted 1059 directed graphs exhibiting the statistical properties observed in the 1060 Web. In particular, the model yields a non-trivial time evolution of 1061 vertices and heavy-tail distributions for the topological and traffic 1062 properties. The generated graphs exhibit a complex architecture with a 1063 hierarchy of cohesiveness levels similar to those observed in the 1064 analysis of real data. 1065 C1 Univ Paris 11, CNRS, Phys Theor Lab, UMR 8627, F-91405 Orsay, France. 1066 CEA, Ctr Etud Bruyeres Le Chatel, Dept Phys Theor & Appl, F-91680 Bruyeres Le Chatel, France. 1067 Indiana Univ, Sch Informat, Bloomington, IN 47408 USA. 1068 RP Barrat, A, Univ Paris 11, CNRS, Phys Theor Lab, UMR 8627, Batiment 210, 1069 F-91405 Orsay, France. 1070 CR ADAMIC IA, 2001, COMMUN ACM, V44, P55 1071 ALBERT R, 2002, REV MOD PHYS, V74, P47 1072 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 1073 BARABASI AL, 1999, SCIENCE, V286, P509 1074 BARABASI AL, 2000, PHYSICA A, V281, P69 1075 BARABASI AL, 2002, PHYSICA A, V311, P590 1076 BARRAT A, CONDMAT0406238 1077 BARRAT A, 2004, P NATL ACAD SCI USA, V101, P3747 1078 BARRAT A, 2004, PHSY REV LETT, V92 1079 BIANCONI G, 2001, EUROPHYS LETT, V54, P436 1080 BRODER A, 2000, P 9 WWW C 1081 COOPER C, 2001, LECT NOTES COMPUTER, V2161, P500 1082 DOROGOVTSEV SN, 2000, EUROPHYS LETT, V52, P33 1083 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 1084 ECKMANN JP, 2002, P NATL ACAD SCI USA, V99, P5825 1085 GARLASCHELLI D, 2003, CONDMAT0310503 1086 GRANOVET.MS, 1973, AM J SOCIOL, V78, P1360 1087 GUIMERA R, 2003, UNPUB 1088 HUBERMAN BA, 1997, SCIENCE, V277, P535 1089 HUBERMAN BA, 1998, SCIENCE, V280, P95 1090 KRAPIVSKY PL, 2001, PHYS REV LETT, V86, P5401 1091 KUMAR R, 2000, P 41 IEEE S FDN COMP, P57 1092 LAURA L, 2002, P 2 INT WORKSH WEB D 1093 LAURA L, 2003, EUR S ALG 1094 MENCZER F, 2002, P NATL ACAD SCI USA, V99, P14014 1095 MOSSA S, 2002, PHYS REV LETT, V88 1096 NEWMAN MEJ, 2001, PHYS REV E 2, V64 1097 NEWMAN MEJ, 2001, PHYS REV E 2, V64 1098 NEWMAN MEJ, 2002, PHYS REV LETT, V89 1099 PANDURANGAN G, 2002, LECT NOTES COMPUTER, V2387, P330 1100 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 1101 PASTORSATORRAS R, 2004, EVOLUTION STRUCTURE 1102 QUINCE C, 2004, ARXIVQBIOPE0402014 1103 RAVASZ E, 2003, PHYS REV E 2, V67 1104 TADIC B, 2001, PHYSICA A, V293, P273 1105 VAZQUEZ A, 2002, PHYS REV E 2, V65 1106 WATTS DJ, 1998, NATURE, V393, P440 1107 YOOK SH, 2001, PHYS REV LETT, V86, P5835 1108 NR 38 1109 TC 4 1110 PU SPRINGER-VERLAG BERLIN 1111 PI BERLIN 1112 PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY 1113 SN 0302-9743 1114 J9 LECT NOTE COMPUT SCI 1115 PY 2004 1116 VL 3243 1117 BP 56 1118 EP 67 1119 PG 12 1120 SC Computer Science, Theory & Methods 1121 GA BBB69 1122 UT ISI:000224583300005 1123 ER 1124 1125 PT J 1126 AU Barrat, A 1127 Barthelemy, M 1128 Vespignani, A 1129 TI Weighted evolving networks: Coupling topology and weight dynamics 1130 SO PHYSICAL REVIEW LETTERS 1131 LA English 1132 DT Article 1133 ID SMALL-WORLD NETWORKS 1134 AB We propose a model for the growth of weighted networks that couples the 1135 establishment of new edges and vertices and the weights' dynamical 1136 evolution. The model is based on a simple weight-driven dynamics and 1137 generates networks exhibiting the statistical properties observed in 1138 several real-world systems. In particular, the model yields a 1139 nontrivial time evolution of vertices' properties and scale-free 1140 behavior for the weight, strength, and degree distributions. 1141 C1 Univ Paris 11, Phys Theor Lab, CNRS, UMR 8627, F-91405 Orsay, France. 1142 Ctr Etud Bruyeres le Chatel, CEA, Dept Phys Theor & Appl, F-91680 Bruyeres Le Chatel, France. 1143 RP Barrat, A, Univ Paris 11, Phys Theor Lab, CNRS, UMR 8627, Batiment 210, 1144 F-91405 Orsay, France. 1145 CR ALBERT R, 2002, REV MOD PHYS, V74, P47 1146 ALMAAS E, 2004, NATURE, V427, P839 1147 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 1148 BARABASI AL, 1999, SCIENCE, V286, P509 1149 BARABASI AL, 2002, PHYSICA A, V311, P590 1150 BARRAT A, IN PRESS 1151 BARRAT A, 2004, P NATL ACAD SCI USA, V101, P3747 1152 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 1153 GARLASCHELLI D, CONDMAT0310503 1154 GRANOVET.MS, 1973, AM J SOCIOL, V78, P1360 1155 GUIMERA R, CONDMAT0312535 1156 KRAUSE AE, 2003, NATURE, V426, P282 1157 LI C, CONDMAT0309236 1158 LI C, CONDMAT0311333 1159 NEWMAN MEJ, 2001, PHYS REV E 2, V64 1160 PASTORSATORRAS R, 2004, EVOLUTION STRUCTURE 1161 PIMM SL, 2002, FOOD WEBS 1162 WATTS DJ, 1998, NATURE, V393, P440 1163 YOOK SH, 2001, PHYS REV LETT, V86, P5835 1164 ZHENG DF, 2003, PHYS REV E 1, V67 1165 NR 20 1166 TC 91 1167 PU AMERICAN PHYSICAL SOC 1168 PI COLLEGE PK 1169 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 1170 SN 0031-9007 1171 J9 PHYS REV LETT 1172 JI Phys. Rev. Lett. 1173 PD JUN 4 1174 PY 2004 1175 VL 92 1176 IS 22 1177 AR 228701 1178 DI ARTN 228701 1179 PG 4 1180 SC Physics, Multidisciplinary 1181 GA 826QU 1182 UT ISI:000221844400064 1183 ER 1184 1185 PT J 1186 AU Moreno, Y 1187 Nekovee, M 1188 Vespignani, A 1189 TI Efficiency and reliability of epidemic data dissemination in complex 1190 networks 1191 SO PHYSICAL REVIEW E 1192 LA English 1193 DT Article 1194 AB We study the dynamics of epidemic spreading processes aimed at 1195 spontaneous dissemination of information updates in populations with 1196 complex connectivity patterns. The influence of the topological 1197 structure of the network in these processes is studied by analyzing the 1198 behavior of several global parameters, such as reliability, efficiency, 1199 and load. Large-scale numerical simulations of update-spreading 1200 processes show that while networks with homogeneous connectivity 1201 patterns permit a higher reliability, scale-free topologies allow for a 1202 better efficiency. 1203 C1 Univ Zaragoza, Dept Fis Teor, E-50009 Zaragoza, Spain. 1204 Univ Zaragoza, Inst Biocomputac & Fis Sistemas Complejos, E-50009 Zaragoza, Spain. 1205 BT Exact, Complex Res Grp, Martlesham IP5 3RE, Suffolk, England. 1206 Univ Paris 11, CNRS, UMR 8627, Phys Theor Lab, F-91405 Orsay, France. 1207 RP Moreno, Y, Univ Zaragoza, Dept Fis Teor, E-50009 Zaragoza, Spain. 1208 CR ALBERT R, 2000, NATURE, V406, P378 1209 BARABASI AL, 1999, PHYSICA A, V272, P173 1210 BARABASI AL, 1999, SCIENCE, V286, P509 1211 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 1212 COHEN R, 2000, PHYS REV LETT, V85, P4626 1213 DALEY DJ, 2000, EPIDEMIC MODELING 1214 DEERING SE, 1990, ACM T COMPUT SYST, V8, P85 1215 DEMERS AJ, 1987, UNPUB P 6 ANN ACM S 1216 FOSTER I, 1999, GRID BLUEPRINT FUTUR 1217 KERMARREC AM, 2003, IEEE T PARALL DISTR, V14, P248 1218 KOSIUR D, 1998, IP MULTICASTING COMP 1219 LIU ZH, 2003, PHYS REV E 1, V67 1220 ORAM A, 2001, PEER TO PEER HARNESS 1221 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 1222 VOGELS W, 2002, UNPUB P HOTNETS I PR 1223 WATTS DJ, 1998, NATURE, V393, P440 1224 ZANETTE DH, 2001, PHYS REV E, V64 1225 NR 17 1226 TC 9 1227 PU AMERICAN PHYSICAL SOC 1228 PI COLLEGE PK 1229 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 1230 SN 1063-651X 1231 J9 PHYS REV E 1232 JI Phys. Rev. E 1233 PD MAY 1234 PY 2004 1235 VL 69 1236 IS 5 1237 PN Part 2 1238 AR 055101 1239 DI ARTN 055101 1240 PG 4 1241 SC Physics, Fluids & Plasmas; Physics, Mathematical 1242 GA 826EZ 1243 UT ISI:000221813400001 1244 ER 1245 1246 PT J 1247 AU Caldarelli, G 1248 Erzan, A 1249 Vespignani, A 1250 TI Preface on "Applications of Networks" 1251 SO EUROPEAN PHYSICAL JOURNAL B 1252 LA English 1253 DT Editorial Material 1254 NR 0 1255 TC 0 1256 PU SPRINGER-VERLAG 1257 PI NEW YORK 1258 PA 175 FIFTH AVE, NEW YORK, NY 10010 USA 1259 SN 1434-6028 1260 J9 EUR PHYS J B 1261 JI Eur. Phys. J. B 1262 PD MAR 1263 PY 2004 1264 VL 38 1265 IS 2 1266 BP 141 1267 EP 141 1268 PG 1 1269 SC Physics, Condensed Matter 1270 GA 821GB 1271 UT ISI:000221447300001 1272 ER 1273 1274 PT J 1275 AU Amaral, LAN 1276 Barrat, A 1277 Barabasi, AL 1278 Caldarelli, G 1279 De los Rios, P 1280 Erzan, A 1281 Kahng, B 1282 Mantegna, R 1283 Mendes, JFF 1284 Pastor-Satorras, R 1285 Vespignani, A 1286 TI Virtual Round Table on ten leading questions for network research 1287 SO EUROPEAN PHYSICAL JOURNAL B 1288 LA English 1289 DT Editorial Material 1290 AB The following discussion is an edited summary of the public debate 1291 started during the conference "Growing Networks and Graphs in 1292 Statistical Physics, Finance, Biology and Social Systems" held in Rome 1293 in September 2003. Drafts documents were circulated electronically 1294 among experts in the field and additions and follow-up to the original 1295 discussion have been included. Among the scientists participating to 1296 the discussion L. A. N. Amaral, A. Barrat, A. L. Barabasi, G. 1297 Caldarelli, P. De Los Rios, A. Erzan, B. Kahng, R. Mantegna, J. F. F. 1298 Mendes, R. Pastor-Satorras, A. Vespignani are acknowledged for their 1299 contributions and editing. 1300 NR 0 1301 TC 12 1302 PU SPRINGER-VERLAG 1303 PI NEW YORK 1304 PA 175 FIFTH AVE, NEW YORK, NY 10010 USA 1305 SN 1434-6028 1306 J9 EUR PHYS J B 1307 JI Eur. Phys. J. B 1308 PD MAR 1309 PY 2004 1310 VL 38 1311 IS 2 1312 BP 143 1313 EP 145 1314 PG 3 1315 SC Physics, Condensed Matter 1316 GA 821GB 1317 UT ISI:000221447300002 1318 ER 1319 1320 PT J 1321 AU Caldarelli, G 1322 Pastor-Satorras, R 1323 Vespignani, A 1324 TI Structure of cycles and local ordering in complex networks 1325 SO EUROPEAN PHYSICAL JOURNAL B 1326 LA English 1327 DT Article 1328 ID WORLD-WIDE-WEB; INTERNET; EVOLUTION; DYNAMICS; TOPOLOGY 1329 AB We study the properties of quantities aimed at the characterization of 1330 grid-like ordering in complex networks. These quantities are based on 1331 the global and local behavior of cycles of order four, which are the 1332 minimal structures able to identify rectangular clustering. The 1333 analysis of data from real networks reveals the ubiquitous presence of 1334 a statistically high level of grid-like ordering that is non-trivially 1335 correlated with the local degree properties. These observations provide 1336 new insights on the hierarchical structure of complex networks. 1337 C1 Univ Roma La Sapienza, Dipartimento Fis, INFM, UdR Roma 1, I-00185 Rome, Italy. 1338 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 1339 Univ Paris 11, CNRS, UMR 8627, Phys Theor Lab, F-91405 Orsay, France. 1340 RP Caldarelli, G, Univ Roma La Sapienza, Dipartimento Fis, INFM, UdR Roma 1341 1, Ple A Moro 2, I-00185 Rome, Italy. 1342 EM romualdo.pastor@upc.es 1343 CR ALBERT R, 1999, NATURE, V401, P130 1344 ALBERT R, 2002, REV MOD PHYS, V74, P47 1345 BARABASI AL, 1999, SCIENCE, V286, P509 1346 BARABASI AL, 2000, PHYSICA A, V281, P69 1347 BARABASI AL, 2002, PHYSICA A, V311, P590 1348 BIANCONI G, 2003, PHYS REV LETT, V90 1349 BOLLOBAS B, 1998, MODERN GRAPH THEORY 1350 DOROGOVTSEV SN, 2002, ADV PHYS, V51, P1079 1351 ERDOS P, 1959, PUBL MATH-DEBRECEN, V6, P290 1352 FALOUTSOS M, 1999, COMP COMM R, V29, P251 1353 HOLME P, CONDMAT0210514 1354 HUBERMAN BA, 1999, NATURE, V401, P131 1355 JEONG H, 2001, NATURE, V411, P41 1356 MOLLOY M, 1995, RANDOM STRUCT ALGOR, V6, P161 1357 NEWMAN MEJ, 2001, PHYS REV E 2, V64 1358 NEWMAN MEJ, 2002, PHYS REV LETT, V89 1359 NEWMAN MEJ, 2003, HDB GRAPHS NETWORKS, P35 1360 NEWMAN MEJ, 2003, PHYS REV E 2, V68 1361 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 1362 RAVASZ E, 2003, PHYS REV E 2, V67 1363 VAZQUEZ A, 2002, CONDMAT0206084 1364 VAZQUEZ A, 2002, PHYS REV E 2, V65 1365 VAZQUEZ A, 2003, COMPLEXUS, V1, P38 1366 WAGNER A, 2001, MOL BIOL EVOL, V18, P1283 1367 WATTS DJ, 1998, NATURE, V393, P440 1368 NR 25 1369 TC 17 1370 PU SPRINGER-VERLAG 1371 PI NEW YORK 1372 PA 175 FIFTH AVE, NEW YORK, NY 10010 USA 1373 SN 1434-6028 1374 J9 EUR PHYS J B 1375 JI Eur. Phys. J. B 1376 PD MAR 1377 PY 2004 1378 VL 38 1379 IS 2 1380 BP 183 1381 EP 186 1382 PG 4 1383 SC Physics, Condensed Matter 1384 GA 821GB 1385 UT ISI:000221447300007 1386 ER 1387 1388 PT J 1389 AU Boguna, M 1390 Pastor-Satorras, R 1391 Vespignani, A 1392 TI Cut-offs and finite size effects in scale-free networks 1393 SO EUROPEAN PHYSICAL JOURNAL B 1394 LA English 1395 DT Article 1396 ID COMPLEX NETWORKS; DEGREE SEQUENCE; RANDOM GRAPHS; INTERNET 1397 AB We analyze the degree distribution's cut-off in finite size scale-free 1398 networks. We show that the cut-off behavior with the number of vertices 1399 N is ruled by the topological constraints induced by the connectivity 1400 structure of the network. Even in the simple case of uncorrelated 1401 networks, we obtain an expression of the structural cut-off that is 1402 smaller than the natural cut-off obtained by means of extremal theory 1403 arguments. The obtained results are explicitly applied in the case of 1404 the configuration model to recover the size scaling of tadpoles and 1405 multiple edges. 1406 C1 Univ Barcelona, Dept Fis Fonamental, E-08028 Barcelona, Spain. 1407 Univ Politecn Cataluna, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 1408 Univ Paris 11, CNRS, UMR 8627, Phys Theor Lab, F-91405 Orsay, France. 1409 RP Boguna, M, Univ Barcelona, Dept Fis Fonamental, Diagonal 647, E-08028 1410 Barcelona, Spain. 1411 EM mbogunya@ffn.ub.es 1412 CR AIELLO W, 2001, EXP MATH, V10, P53 1413 ALBERT R, 2000, PHYS REV LETT, V85, P5234 1414 ALBERT R, 2002, REV MOD PHYS, V74, P47 1415 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 1416 BARABASI AL, 1999, SCIENCE, V286, P509 1417 BOGUNA M, 2003, LECT NOTES PHYS, V625 1418 BOGUNA M, 2003, PHYS REV E 2, V68 1419 BOGUNA M, 2003, PHYS REV LETT, V90 1420 BURDA Z, 2003, PHYS REV E 2, V67 1421 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 1422 CHUNG F, 2002, ANN COMB, V6, P125 1423 COHEN R, 2000, PHYS REV LETT, V85, P4626 1424 DOROGOVTSEV SN, 2002, ADV PHYS, V51, P1079 1425 DOROGOVTSEV SN, 2002, PHYS REV E 2, V66 1426 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 1427 KRAPIVSKY PL, 2002, J PHYS A-MATH GEN, V35, P9517 1428 LEONE M, 2002, EUR PHYS J B, V28, P191 1429 MASLOV S, 2004, PHYSICA A, V333, P529 1430 MAY RM, 2001, PHYS REV E, V64 1431 MOLLOY M, 1995, RANDOM STRUCT ALGOR, V6, P161 1432 MOLLOY M, 1998, COMB PROBAB COMPUT, V7, P295 1433 MOREIRA AA, 2002, PHYS REV LETT, V89 1434 MORENO Y, 2002, EUR PHYS J B, V26, P521 1435 MOSSA S, 2002, PHYS REV LETT, V88 1436 NEWMAN MEJ, 2002, PHYS REV E, V64 1437 NEWMAN MEJ, 2002, PHYS REV LETT, V89 1438 NEWMAN MEJ, 2003, PHYS REV E 2, V67 1439 PARK J, 2003, PHYS REV E, V66 1440 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 1441 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 1442 PASTORSATORRAS R, 2002, PHYS REV E 2A, V65 1443 VAZQUEZ A, 2003, PHYS REV E, V67 1444 NR 32 1445 TC 42 1446 PU SPRINGER-VERLAG 1447 PI NEW YORK 1448 PA 175 FIFTH AVE, NEW YORK, NY 10010 USA 1449 SN 1434-6028 1450 J9 EUR PHYS J B 1451 JI Eur. Phys. J. B 1452 PD MAR 1453 PY 2004 1454 VL 38 1455 IS 2 1456 BP 205 1457 EP 209 1458 PG 5 1459 SC Physics, Condensed Matter 1460 GA 821GB 1461 UT ISI:000221447300011 1462 ER 1463 1464 PT J 1465 AU Barthelemy, M 1466 Barrat, A 1467 Pastor-Satorras, R 1468 Vespignani, A 1469 TI Velocity and hierarchical spread of epidemic outbreaks in scale-free 1470 networks 1471 SO PHYSICAL REVIEW LETTERS 1472 LA English 1473 DT Article 1474 ID SMALL-WORLD NETWORKS; COMPLEX NETWORKS 1475 AB We study the effect of the connectivity pattern of complex networks on 1476 the propagation dynamics of epidemics. The growth time scale of 1477 outbreaks is inversely proportional to the network degree fluctuations, 1478 signaling that epidemics spread almost instantaneously in networks with 1479 scale-free degree distributions. This feature is associated with an 1480 epidemic propagation that follows a precise hierarchical dynamics. Once 1481 the highly connected hubs are reached, the infection pervades the 1482 network in a progressive cascade across smaller degree classes. The 1483 present results are relevant for the development of adaptive 1484 containment strategies. 1485 C1 CEA, Ctr Etud Bruyeres le Chatel, Dept Phys Theor & Appl, F-91680 Bruyeres Le Chatel, France. 1486 Univ Paris 11, CNRS, UMR 8627, Phys Theor Lab, F-91405 Orsay, France. 1487 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 1488 RP Barthelemy, M, CEA, Ctr Etud Bruyeres le Chatel, Dept Phys Theor & 1489 Appl, BP12, F-91680 Bruyeres Le Chatel, France. 1490 CR ALBERT R, 2002, REV MOD PHYS, V74, P47 1491 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 1492 ANDERSON RM, 1992, INFECT DIS HUMANS 1493 BARABASI AL, 1999, SCIENCE, V286, P509 1494 BOGUNA M, 2003, LECT NOTES PHYS, V625, P127 1495 COHEN R, 2003, PHYS REV LETT, V91 1496 DERRIDA B, 1987, J PHYS A-MATH GEN, V20, P5273 1497 DEZSO Z, 2002, PHYS REV E 2, V65 1498 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 1499 HETHCOTE HW, 1984, LECT NOTES BIOMATHS, V56, P1 1500 KUPERMAN M, 2001, PHYS REV LETT, V86, P2909 1501 LILJEROS F, 2001, NATURE, V411, P907 1502 LLOYD AL, 2001, SCIENCE, V292, P1316 1503 MAY RM, 2001, PHYS REV E 2, V64 1504 MOORE C, 2000, PHYS REV E B, V61, P5678 1505 MORENO Y, 2002, EUR PHYS J B, V26, P521 1506 MURRAY JD, 1993, MATH BIOL 1507 NEWMAN MEJ, 2002, PHYS REV E, V64 1508 PASTORSATORRAS R, 2001, PHYS REV E 2, V63 1509 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 1510 PASTORSATORRAS R, 2002, PHYS REV E 2A, V65 1511 PASTORSATORRAS R, 2003, EVOLUTION STRUCTURE 1512 NR 22 1513 TC 52 1514 PU AMERICAN PHYSICAL SOC 1515 PI COLLEGE PK 1516 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 1517 SN 0031-9007 1518 J9 PHYS REV LETT 1519 JI Phys. Rev. Lett. 1520 PD APR 30 1521 PY 2004 1522 VL 92 1523 IS 17 1524 AR 178701 1525 DI ARTN 178701 1526 PG 4 1527 SC Physics, Multidisciplinary 1528 GA 817LO 1529 UT ISI:000221179200069 1530 ER 1531 1532 PT J 1533 AU Barrat, A 1534 Barthelemy, M 1535 Pastor-Satorras, R 1536 Vespignani, A 1537 TI The architecture of complex weighted networks 1538 SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF 1539 AMERICA 1540 LA English 1541 DT Article 1542 ID SMALL-WORLD NETWORKS; BETWEENNESS 1543 AB Networked structures arise in a wide array of different contexts such 1544 as technological and transportation infrastructures, social phenomena, 1545 and biological systems. These highly interconnected systems have 1546 recently been the focus of a great deal of attention that has uncovered 1547 and characterized their topological complexity. Along with a complex 1548 topological structure, real networks display a large heterogeneity in 1549 the capacity and intensity of the connections. These features, however, 1550 have mainly not been considered in past studies where links are usually 1551 represented as binary states, i.e., either present or absent. Here, we 1552 study the scientific collaboration network and the world-wide 1553 air-transportation network, which are representative examples of social 1554 and large infrastructure systems, respectively. In both cases it is 1555 possible to assign to each edge of the graph a weight proportional to 1556 the intensity or capacity of the connections among the various elements 1557 of the network. We define appropriate metrics combining weighted and 1558 topological observables that enable us to characterize the complex 1559 statistical properties and heterogeneity of the actual strength of 1560 edges and vertices. This information allows us to investigate the 1561 correlations among weighted quantities and the underlying topological 1562 structure of the network. These results provide a better description of 1563 the hierarchies and organizational principles at the basis of the 1564 architecture of weighted networks. 1565 C1 Univ Paris 11, UMR CNRS 8627, Phys Theor Lab, F-91405 Orsay, France. 1566 CEA, Dept Phys Theor & Appl, F-91191 Gif Sur Yvette, France. 1567 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 1568 RP Vespignani, A, Univ Paris 11, UMR CNRS 8627, Phys Theor Lab, Batiment 1569 210, F-91405 Orsay, France. 1570 EM alexv@th.u-psud.fr 1571 CR ALBERT R, 2000, NATURE, V406, P378 1572 ALBERT R, 2002, REV MOD PHYS, V74, P47 1573 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 1574 BARABASI AL, 1999, SCIENCE, V286, P509 1575 BARABASI AL, 2002, PHYSICA A, V311, P590 1576 BRANDES U, 2001, J MATH SOCIOL, V25, P163 1577 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 1578 CLARK J, 1998, 1 LOOK GRAPH THEORY 1579 COHEN R, 2000, PHYS REV LETT, V85, P4626 1580 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS B 1581 FREEMAN LC, 1977, SOCIOMETRY, V40, P35 1582 GOH KI, 2001, PHYS REV LETT, V87 1583 GUIMERA R, 2003, E PRINT ARCH 1584 LI W, 2003, E PRINT ARCH 1585 MASLOV S, 2002, SCIENCE, V296, P910 1586 NEWMAN MEJ, 2001, PHYS REV E 2, V64 1587 NEWMAN MEJ, 2001, PHYS REV E 2, V64 1588 NEWMAN MEJ, 2002, PHYS REV LETT, V89 1589 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 1590 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 1591 RAVASZ E, 2003, PHYS REV E 2, V67 1592 VAZQUEZ A, 2002, PHYS REV E 2, V65 1593 WATTS DJ, 1998, NATURE, V393, P440 1594 YOOK SH, 2001, PHYS REV LETT, V86, P5835 1595 ZHOU S, 2003, E PRINT ARCH 1596 NR 25 1597 TC 190 1598 PU NATL ACAD SCIENCES 1599 PI WASHINGTON 1600 PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA 1601 SN 0027-8424 1602 J9 PROC NAT ACAD SCI USA 1603 JI Proc. Natl. Acad. Sci. U. S. A. 1604 PD MAR 16 1605 PY 2004 1606 VL 101 1607 IS 11 1608 BP 3747 1609 EP 3752 1610 PG 6 1611 SC Multidisciplinary Sciences 1612 GA 804QZ 1613 UT ISI:000220314500008 1614 ER 1615 1616 PT J 1617 AU Vespignani, A 1618 TI Evolution thinks modular 1619 SO NATURE GENETICS 1620 LA English 1621 DT Editorial Material 1622 ID PROTEIN-INTERACTION NETWORKS; PREDICTION 1623 AB Groups of interacting proteins define functional modules that govern a 1624 cell's activity. A new study suggests that specific interaction motifs 1625 and their constituents are highly conserved across species, identifying 1626 potential functional modules used in the evolutionary process. 1627 C1 Univ Paris 11, Phys Theor Lab, F-91405 Orsay, France. 1628 RP Vespignani, A, Univ Paris 11, Phys Theor Lab, Batiment 210, F-91405 1629 Orsay, France. 1630 CR BARABASI AL, 2002, LINKED 1631 DOROGOVTSEV SN, 2003, EVOLUTION NETWORKS 1632 HARTWELL LH, 1999, NATURE, V402, P47 1633 HISHIGAKI H, 2001, YEAST, V18, P523 1634 HODGMAN TC, 2000, BIOINFORMATICS, V16, P10 1635 MILO R, 2002, SCIENCE, V298, P824 1636 OLTVAI ZN, 2002, SCIENCE, V298, P763 1637 PASTORSATORRAS R, 2003, J THEOR BIOL, V222, P199 1638 RAVASZ E, 2002, SCIENCE, V297, P1551 1639 VAZQUEZ A, 2003, COMPLEXUS, V1, P38 1640 VAZQUEZ A, 2003, NAT BIOTECHNOL, V21, P697 1641 WUCHTY S, 2003, NAT GENET, V35, P176 1642 NR 12 1643 TC 12 1644 PU NATURE PUBLISHING GROUP 1645 PI NEW YORK 1646 PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA 1647 SN 1061-4036 1648 J9 NAT GENET 1649 JI Nature Genet. 1650 PD OCT 1651 PY 2003 1652 VL 35 1653 IS 2 1654 BP 118 1655 EP 119 1656 PG 2 1657 SC Genetics & Heredity 1658 GA 726WV 1659 UT ISI:000185625300005 1660 ER 1661 1662 PT J 1663 AU Bagnoli, F 1664 Cecconi, F 1665 Flammini, A 1666 Vespignani, A 1667 TI Short-period attractors and non-ergodic behavior in the deterministic 1668 fixed-energy sandpile model 1669 SO EUROPHYSICS LETTERS 1670 LA English 1671 DT Article 1672 ID SELF-ORGANIZED CRITICALITY; ABSORBING PHASE-TRANSITIONS; CHARGE-DENSITY 1673 WAVES; ABELIAN SANDPILE; CONSERVED FIELD; AVALANCHES; LOCKING; EVENTS 1674 AB We study the asymptotic behaviour of the Bak, Tang, Wiesenfeld sandpile 1675 automata as a closed system with fixed energy. We explore the full 1676 range of energies characterizing the active phase. The model exhibits 1677 strong non-ergodic features by settling into limit-cycles whose period 1678 depends on the energy and initial conditions. The asymptotic activity 1679 rho(a) (topplings density) shows, as a function of energy density zeta, 1680 a devil's staircase behaviour de. ning a symmetric energy interval-set 1681 over which also the period lengths remain constant. The properties of 1682 the zeta-rho(a) phase diagram can be traced back to the basic 1683 symmetries underlying the model's dynamics. 1684 C1 Dipartimento Energet S Stecco, I-50139 Florence, Italy. 1685 Univ Roma La Sapienza, INFM, I-00185 Rome, Italy. 1686 Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. 1687 INFM, I-34014 Trieste, Italy. 1688 Int Sch Adv Studies SISSA ISAS, I-34014 Trieste, Italy. 1689 Univ Paris 11, Phys Theor Lab, UMR 8627, CNRS, F-91405 Orsay, France. 1690 RP Bagnoli, F, Dipartimento Energet S Stecco, Via S Marta 3, I-50139 1691 Florence, Italy. 1692 CR ALAVA M, 2002, J PHYS-CONDENS MAT, V14, P2353 1693 BAK P, 1986, PHYS TODAY, V39, P38 1694 BAK P, 1987, PHYS REV LETT, V59, P381 1695 CECCONI F, 1998, PHYS REV E A, V57, P2703 1696 CHESSA A, 1998, PHYS REV LETT, V80, P4217 1697 DEMENECH M, 1998, PHYS REV E A, V58, R2677 1698 DHAR D, CONDMAT990909 1699 DHAR D, 1999, PHYSICA A, V263, P4 1700 DICKMAN R, 1998, PHYS REV E A, V57, P5095 1701 ERZAN A, 1991, PHYS REV LETT, V66, P2750 1702 GRINSTEIN G, 1999, NATO ASI B, V344 1703 HIGGINS MJ, 1993, PHYS REV LETT, V70, P3784 1704 HWA T, 1992, PHYS REV A, V45, P7002 1705 JENSEN HJ, 1999, SELF ORG CRITICALITY 1706 KTITAREV DV, 2000, PHYS REV E, V61, P81 1707 LORETO V, 1996, PHYS REV E, V53, P2087 1708 LUBECK S, 2001, PHYS REV E 2, V64 1709 LUBECK S, 2002, PHYS REV E 2A, V65 1710 MANNA SS, 1991, J PHYS A, V24, L363 1711 MARRO J, 1999, NONEQUILIBRIUM PHASE 1712 MIDDLETON AA, 1992, PHYS REV LETT, V68, P1586 1713 MONTAKHAB A, 1998, PHYS REV E A, V58, P5608 1714 NARAYAN O, 1994, PHYS REV B, V49, P244 1715 PASTORSATORRAS R, 2000, PHYS REV E A, V62, R5875 1716 ROSSI M, 2000, PHYS REV LETT, V85, P1803 1717 SHUSTER HG, 1988, DETERMINISTIC CHAOS 1718 TANG C, 1988, PHYS REV LETT, V60, P2347 1719 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 1720 VESPIGNANI A, 1998, PHYS REV E, V57, P6345 1721 VESPIGNANI A, 1998, PHYS REV LETT, V81, P5676 1722 VESPIGNANI A, 2000, PHYS REV E A, V62, P4564 1723 NR 31 1724 TC 7 1725 PU E D P SCIENCES 1726 PI LES ULIS CEDEXA 1727 PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES 1728 ULIS CEDEXA, FRANCE 1729 SN 0295-5075 1730 J9 EUROPHYS LETT 1731 JI Europhys. Lett. 1732 PD AUG 1733 PY 2003 1734 VL 63 1735 IS 4 1736 BP 512 1737 EP 518 1738 PG 7 1739 SC Physics, Multidisciplinary 1740 GA 709GU 1741 UT ISI:000184618100006 1742 ER 1743 1744 PT J 1745 AU Castellano, C 1746 Vilone, D 1747 Vespignani, A 1748 TI Incomplete ordering of the voter model on small-world networks 1749 SO EUROPHYSICS LETTERS 1750 LA English 1751 DT Article 1752 ID COMPLEX NETWORKS 1753 AB We investigate how the topology of small-world networks affects the 1754 dynamics of the voter model for opinion formation. We show that, 1755 contrary to what occurs on regular topologies with local interactions, 1756 the voter model on small-world networks does not display the emergence 1757 of complete order in the thermodynamic limit. The system settles in a 1758 stationary state with coexisting opinions whose lifetime diverges with 1759 the system size. Hence the nontrivial connectivity pattern leads to the 1760 counterintuitive conclusion that long-range connections inhibit the 1761 ordering process. However, for networks of finite size, for which full 1762 uniformity is reached, the ordering process takes a time shorter than 1763 on a regular lattice of the same size. 1764 C1 Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. 1765 INFM, Unita Roma 1, I-00185 Rome, Italy. 1766 Univ Paris 11, Phys Theor Lab, UMR 8627, CNRS, F-91405 Orsay, France. 1767 RP Castellano, C, Univ Roma La Sapienza, Dipartimento Fis, P A Moro 2, 1768 I-00185 Rome, Italy. 1769 CR ALBERT R, 2002, REV MOD PHYS, V74, P47 1770 AXELROD R, 1997, COMPLEXITY COOPERATI 1771 AXELROD R, 1997, J CONFLICT RESOLUT, V41, P203 1772 AXTELL R, 1996, COMPUTATIONAL MATH O, V1, P123 1773 BARRAT A, 2000, EUR PHYS J B, V13, P547 1774 BARTHELEMY M, 1999, PHYS REV LETT, V82, P3180 1775 BOYER D, 2003, PHYS REV E 2, V67 1776 BRAY AJ, 1994, ADV PHYS, V43, P357 1777 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 1778 CASTELLANO C, 2000, PHYS REV LETT, V85, P3536 1779 COHEN R, 2000, PHYS REV LETT, V85, P4626 1780 DORNIC I, 2001, PHYS REV LETT, V87 1781 FRACHEBOURG L, 1996, PHYS REV E, V53, P3009 1782 HOLYST JA, 2001, ANN REV COMPUTATIONA, V9 1783 LIGGETT TM, 1985, INTERACTING PARTICLE 1784 LILJEROS F, 2001, NATURE, V411, P907 1785 MARRO J, 1999, NONEQUILIBRIUM PHASE 1786 NEWMAN MEJ, 2000, J STAT PHYS, V101, P819 1787 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 1788 REDNER S, 1998, EUR PHYS J B, V4, P131 1789 REDNER S, 2001, GUIDE 1ST PASSAGE PR 1790 SANCHEZ AD, 2002, PHYS REV LETT, V88 1791 STAUFFER D, 2002, JASSS, V5, P1 1792 STROGATZ SH, 2001, NATURE, V410, P268 1793 VAZQUEZ F, 2002, CONDMAT0209445 1794 WATTS DJ, 1998, NATURE, V393, P440 1795 WATTS DJ, 1999, SMALL WORLDS DYNAMIC 1796 NR 27 1797 TC 22 1798 PU E D P SCIENCES 1799 PI LES ULIS CEDEXA 1800 PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES 1801 ULIS CEDEXA, FRANCE 1802 SN 0295-5075 1803 J9 EUROPHYS LETT 1804 JI Europhys. Lett. 1805 PD JUL 1806 PY 2003 1807 VL 63 1808 IS 1 1809 BP 153 1810 EP 158 1811 PG 6 1812 SC Physics, Multidisciplinary 1813 GA 696HC 1814 UT ISI:000183880700023 1815 ER 1816 1817 PT J 1818 AU Vazquez, A 1819 Flammini, A 1820 Maritan, A 1821 Vespignani, A 1822 TI Global protein function prediction from protein-protein interaction 1823 networks 1824 SO NATURE BIOTECHNOLOGY 1825 LA English 1826 DT Article 1827 ID SACCHAROMYCES-CEREVISIAE; YEAST; COMPLEXES; GENOME 1828 AB Determining protein function is one of the most challenging problems of 1829 the post-genomic era. The availability of entire genome sequences and 1830 of high-throughput capabilities to determine gene coexpression patterns 1831 has shifted the research focus from the study of single proteins or 1832 small complexes to that of the entire proteome(1). In this context, the 1833 search for reliable methods for assigning protein function is of 1834 primary importance. There are various approaches available for deducing 1835 the function of proteins of unknown function using information derived 1836 from sequence similarity or clustering patterns of coregulated 1837 genes(2,3), phylogenetic profiles(4), protein-protein interactions 1838 (refs. 5-8 and Samanta, M. P. and Liang, S., unpublished data), and 1839 protein complexes(9,10). Here we propose the assignment of proteins to 1840 functional classes on the basis of their network of physical 1841 interactions as determined by minimizing the number of protein 1842 interactions among different functional categories. Function assignment 1843 is proteome-wide and is determined by the global connectivity pattern 1844 of the protein network. The approach results in multiple functional 1845 assignments, a consequence of the existence of multiple equivalent 1846 solutions. We apply the method to analyze the yeast Saccharomyces 1847 cerevisiae protein-protein interaction network(5). The robustness of 1848 the approach is tested in a system containing a high percentage of 1849 unclassified proteins and also in cases of deletion and insertion of 1850 specific protein interactions. 1851 C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. 1852 SISSA, I-34014 Trieste, Italy. 1853 INFM, I-34014 Trieste, Italy. 1854 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 1855 Univ Paris 11, Phys Theor Lab, UMR CNRS 8627, F-91405 Orsay, France. 1856 RP Vazquez, A, Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. 1857 CR *MIPS, MIPS COMPR YEAST GEN 1858 GAVIN AC, 2002, NATURE, V415, P141 1859 HARRINGTON CA, 2000, CURR OPIN MICROBIOL, V3, P285 1860 HISHIGAKI H, 2001, YEAST, V18, P523 1861 HO Y, 2002, NATURE, V415, P180 1862 HODGMAN TC, 2000, BIOINFORMATICS, V16, P10 1863 ITO T, 2001, P NATL ACAD SCI USA, V98, P4569 1864 JEONG H, 2001, NATURE, V411, P41 1865 KIRKPATRICK S, 1983, SCIENCE, V220, P621 1866 MEYER ML, 2000, NAT BIOTECHNOL, V18, P1242 1867 PELLEGRINI M, 1999, P NATL ACAD SCI USA, V96, P4285 1868 SCHWIKOWSKI B, 2000, NAT BIOTECHNOL, V18, P1257 1869 UETZ P, 2000, NATURE, V403, P623 1870 WAGNER A, 2000, NAT GENET, V24, P355 1871 WU FY, 1982, REV MOD PHYS, V54, P235 1872 ZHANG MQ, 1999, COMPUT CHEM, V23, P233 1873 NR 16 1874 TC 96 1875 PU NATURE PUBLISHING GROUP 1876 PI NEW YORK 1877 PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA 1878 SN 1087-0156 1879 J9 NAT BIOTECHNOL 1880 JI Nat. Biotechnol. 1881 PD JUN 1882 PY 2003 1883 VL 21 1884 IS 6 1885 BP 697 1886 EP 700 1887 PG 4 1888 SC Biotechnology & Applied Microbiology 1889 GA 684RR 1890 UT ISI:000183220800030 1891 ER 1892 1893 PT J 1894 AU Percacci, R 1895 Vespignani, A 1896 TI Scale-free behavior of the Internet global performance 1897 SO EUROPEAN PHYSICAL JOURNAL B 1898 LA English 1899 DT Article 1900 AB Measurements and data analysis have proved very effective in the study 1901 of the Internet's physical fabric and have shown heterogeneities and 1902 statistical fluctuations extending over several orders of magnitude. 1903 Here we focus on the relationship between the, Round-Trip-Time (RTT) 1904 and the geographical distance. We define dimensionless variables that 1905 contain information on the quality of Internet connections finding that 1906 their probability distributions are characterized by a slow power-law 1907 decay signalling the presence of scale-free features. These results 1908 point out the extreme heterogeneity of Internet delay since the 1909 transmission speed between different points of the network exhibits 1910 very large fluctuations' The associated scaling exponents appear to 1911 have fairly stable values in different data sets and thus define an 1912 invariant characteristic of the Internet that might be used in the 1913 future as a benchmark of the overall state of "health" of the Internet. 1914 C1 SISSA, Int Sch Adv Studies, ISAS, I-34014 Trieste, Italy. 1915 Univ Paris 11, Phys Theor Lab, F-91405 Orsay, France. 1916 RP Percacci, R, SISSA, Int Sch Adv Studies, ISAS, Via Beirut 4, I-34014 1917 Trieste, Italy. 1918 CR ALBERT R, 2002, REV MOD PHYS, V74, P47 1919 BARABASI AL, 2002, AREV MOD PHYS, V74, P47 1920 BOVY C, 2002, P PAM 2002 C FORT CO 1921 BROIDO A, 2001, SPIE INT S CONV IT C 1922 CROVELLA M, 2000, PERFORM EVALUATION, V42, P91 1923 FALOUTSOS M, 1999, COMP COMM R, V29, P251 1924 FLOYD S, 2001, IEEE ACM T NETWORK, V9, P392 1925 GOVINDAN R, 2000, P IEEE INFOCOM 2000 1926 HUFFAKER B, 2001, P PAM 2001 C AMST 23 1927 LEE C, 2001, 10 IEEE HET COMP WOR 1928 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 1929 PAXSON V, 1997, IEEE ACM T NETWORK, V5, P601 1930 VESPIGNANI A, 2002, PHYS REV E, V65 1931 WILLINGER W, 1996, STOCHASTIC NETWORKS, P339 1932 WILLINGER W, 2002, P NATL ACAD SCI U S1, V99, P2573 1933 WILLINGER W, 2002, P NATL ACAD SCI U S1, V99, P2573 1934 NR 16 1935 TC 3 1936 PU SPRINGER-VERLAG 1937 PI NEW YORK 1938 PA 175 FIFTH AVE, NEW YORK, NY 10010 USA 1939 SN 1434-6028 1940 J9 EUR PHYS J B 1941 JI Eur. Phys. J. B 1942 PD APR 1943 PY 2003 1944 VL 32 1945 IS 4 1946 BP 411 1947 EP 414 1948 PG 4 1949 SC Physics, Condensed Matter 1950 GA 686NF 1951 UT ISI:000183327300001 1952 ER 1953 1954 PT J 1955 AU Vazquez, A 1956 Boguna, M 1957 Moreno, Y 1958 Pastor-Satorras, R 1959 Vespignani, A 1960 TI Topology and correlations in structured scale-free networks 1961 SO PHYSICAL REVIEW E 1962 LA English 1963 DT Article 1964 ID COMPLEX NETWORKS; INTERNET; DYNAMICS; ATTACK 1965 AB We study a recently introduced class of scale-free networks showing a 1966 high clustering coefficient and nontrivial connectivity correlations. 1967 We find that the connectivity probability distribution strongly depends 1968 on the fine details of the model. We solve exactly the case of low 1969 average connectivity, providing also exact expressions for the 1970 clustering and degree correlation functions. The model also exhibits a 1971 lack of small-world properties in the whole parameter range. We discuss 1972 the physical properties of these networks in the light of the present 1973 detailed analysis. 1974 C1 Scuola Int Super Studi Avanzati, I-34014 Trieste, Italy. 1975 INFM, I-34014 Trieste, Italy. 1976 Univ Barcelona, Dept Fis Fonamental, E-08028 Barcelona, Spain. 1977 Abdus Salam Int Ctr Theoret Phys, I-34014 Trieste, Italy. 1978 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 1979 Univ Paris 11, Phys Theor Lab, UMR CNRS 8627, F-91405 Orsay, France. 1980 RP Vazquez, A, Scuola Int Super Studi Avanzati, Via Beirut 4, I-34014 1981 Trieste, Italy. 1982 CR ABRAMOWITZ M, 1972, HDB MATH FUNCTIONS 1983 ALBERT R, 1999, NATURE, V401, P130 1984 ALBERT R, 2000, NATURE, V406, P378 1985 ALBERT R, 2002, REV MOD PHYS, V74, P47 1986 BARABASI AL, 1999, SCIENCE, V286, P509 1987 BOGUNA M, 2002, PHYS REV E 2, V66 1988 BOGUNA M, 2003, PHYS REV LETT, V90 1989 CALDARELLI G, 2000, EUROPHYS LETT, V52, P386 1990 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 1991 CHARTRAND G, 1986, GRAPHS DIGRAPHS 1992 COHEN R, 2001, PHYS REV LETT, V86, P3682 1993 CRUCITTI P, CONDMAT0205601 1994 DEZSO Z, 2002, PHYS REV E, V65 1995 DOROGOVTSEV SN, 2002, ADV PHYS, V51, P1079 1996 EGUILUZ VM, 2002, PHYS REV LETT, V89 1997 ERDOS P, 1960, PUBL MATH I HUNG, V5, P17 1998 FALOUTSOS M, 1999, COMP COMM R, V29, P251 1999 JEONG H, 2001, NATURE, V411, P41 2000 KLEMM K, 2002, PHYS REV E 2, V65 2001 KLEMM K, 2002, PHYS REV E 2A, V65 2002 LLOYD AL, 2001, SCIENCE, V292, P1316 2003 MARRO J, 1999, NONEQUILIBRIUM PHASE 2004 MAY RM, 2001, PHYS REV E 2, V64 2005 MONTOYA JM, 2002, J THEOR BIOL, V214, P405 2006 MORENO Y, 2002, EUR PHYS J B, V26, P521 2007 NEWMAN MEJ, 2002, PHYS REV LETT, V89 2008 PASTORSATORRAS R, 2001, PHYS REV E 2, V63 2009 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 2010 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 2011 PASTORSATORRAS R, 2002, PHYS REV E 2A, V65 2012 RAVASZ E, CONDMAT0206130 2013 SOLE RV, 2002, ADV COMPLEX SYST, V5, P43 2014 STROGATZ SH, 2001, NATURE, V410, P268 2015 VAZQUEZ A, 2002, PHYS REV E 2, V65 2016 VAZQUEZ A, 2003, COMPLEXUS, V1, P38 2017 WAGNER A, 2001, MOL BIOL EVOL, V18, P1283 2018 WARREN CP, 2002, PHYS REV E, V66 2019 WATTS DJ, 1998, NATURE, V393, P440 2020 NR 38 2021 TC 30 2022 PU AMERICAN PHYSICAL SOC 2023 PI COLLEGE PK 2024 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 2025 SN 1063-651X 2026 J9 PHYS REV E 2027 JI Phys. Rev. E 2028 PD APR 2029 PY 2003 2030 VL 67 2031 IS 4 2032 PN Part 2 2033 AR 046111 2034 DI ARTN 046111 2035 PG 10 2036 SC Physics, Fluids & Plasmas; Physics, Mathematical 2037 GA 677UD 2038 UT ISI:000182825400024 2039 ER 2040 2041 PT J 2042 AU Moreno, Y 2043 Pastor-Satorras, R 2044 Vazquez, A 2045 Vespignani, A 2046 TI Critical load and congestion instabilities in scale-free networks 2047 SO EUROPHYSICS LETTERS 2048 LA English 2049 DT Article 2050 ID COMPLEX NETWORKS; OVERLOAD BREAKDOWN; EVOLVING NETWORKS; 2051 PHASE-TRANSITION; INTERNET; MODEL; WEB 2052 AB We study the tolerance to congestion failures in communication networks 2053 with scale-free topology. The traffic load carried by each damaged 2054 element in the network must be partly or totally redistributed among 2055 the remaining elements. Overloaded elements might fail on their turn, 2056 triggering the occurrence of failure cascades able to isolate large 2057 parts of the network. We find a critical traffic load above which the 2058 probability of massive traffic congestions destroying the network 2059 communication capabilities is finite. 2060 C1 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 2061 Univ Zaragoza, Dept Fis Teor, E-50009 Zaragoza, Spain. 2062 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 2063 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. 2064 Univ Paris 11, Phys Theor Lab, CNRS, UMR 8627, F-91405 Orsay, France. 2065 RP Moreno, Y, Abdus Salam Int Ctr Theoret Phys, POB 586, I-34100 Trieste, 2066 Italy. 2067 CR ALBERT R, 2000, NATURE, V406, P378 2068 ALBERT R, 2002, REV MOD PHYS, V74, P47 2069 BARABASI AL, 1999, PHYSICA A, V272, P173 2070 BARABASI AL, 2000, PHYSICA A, V281, P69 2071 BRODER A, 2000, COMPUT NETW, V33, P309 2072 BROIDO A, 2001, SPIE INT S CONV IT C 2073 CALDARELLI G, 2000, EUROPHYS LETT, V52, P386 2074 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 2075 CHEN Q, 2002, P INFOCOM 2002 21 AN, V2 2076 COHEN R, 2000, PHYS REV LETT, V85, P4626 2077 DOROGOVTSEV SN, 2002, ADV PHYS, V51, P1079 2078 FALOUTSOS M, 1999, COMP COMM R, V29, P251 2079 GOH KI, 2001, PHYS REV LETT, V87 2080 GOVINDAN R, 2000, P IEEE INFOCOM 2000 2081 HOLME P, 2002, PHYS REV E 2, V65 2082 HOLME P, 2002, PHYS REV E 2A, V66 2083 JENSEN HJ, 1998, SELF ORG CRITICALITY 2084 LABOVITZ C, 1999, 29 ANN INT S FAULT T, V278 2085 LABOVITZ C, 1999, P INFOCOM 99 18 ANN, V1 2086 MAGNASCO MO, 2000, NLINAO0010051 2087 MARRO J, 1999, NONEQUILIBRIUM PHASE 2088 MORENO Y, 2002, EUROPHYS LETT, V58, P630 2089 NEWMAN MEJ, 2001, PHYS REV E 2, V64 2090 OHIRA T, 1998, PHYS REV E, V58, P193 2091 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 2092 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 2093 PASTORSATORRAS R, 2002, HDB GRAPHS NETWORKS 2094 STROGATZ SH, 2001, NATURE, V410, P268 2095 TADIC B, 2002, CONDMAT02072287 2096 TAKAYASU M, 1996, PHYSICA A, V233, P924 2097 TRETYAKOV AY, 1998, PHYSICA A, V253, P315 2098 VAZQUEZ A, 2002, PHYS REV E 2, V65 2099 WATTS DJ, 2002, P NATL ACAD SCI USA, V99, P5766 2100 WILLINGER W, 2002, P NATL ACAD SCI U S1, V99, P2573 2101 NR 34 2102 TC 37 2103 PU E D P SCIENCES 2104 PI LES ULIS CEDEXA 2105 PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES 2106 ULIS CEDEXA, FRANCE 2107 SN 0295-5075 2108 J9 EUROPHYS LETT 2109 JI Europhys. Lett. 2110 PD APR 2111 PY 2003 2112 VL 62 2113 IS 2 2114 BP 292 2115 EP 298 2116 PG 7 2117 SC Physics, Multidisciplinary 2118 GA 665NK 2119 UT ISI:000182127200022 2120 ER 2121 2122 PT J 2123 AU Vilone, D 2124 Vespignani, A 2125 Castellano, C 2126 TI Ordering phase transition in the one-dimensional Axelrod model 2127 SO EUROPEAN PHYSICAL JOURNAL B 2128 LA English 2129 DT Article 2130 AB We study the one-dimensional behavior of a cellular automaton aimed at 2131 the description of the formation and evolution of cultural domains. The 2132 model exhibits a non-equilibrium transition between a phase with all 2133 the system sharing the same culture and a disordered phase of 2134 coexisting regions with different cultural features. Depending on the 2135 initial distribution of the disorder the transition occurs at different 2136 values of the model parameters. This phenomenology is qualitatively 2137 captured by a mean-field approach, which maps the dynamics into a 2138 multi-species reaction-diffusion problem. 2139 C1 Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. 2140 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 2141 INFM, Unita Roma 1, I-00185 Rome, Italy. 2142 RP Vilone, D, Univ Roma La Sapienza, Dipartimento Fis, P A Moro 2, I-00185 2143 Rome, Italy. 2144 CR AXELROD R, 1997, COMPLEXITY COOPERATI 2145 AXELROD R, 1997, J CONFLICT RESOLUT, V41, P207 2146 AXTELL R, 1996, COMPUTATIONAL MATH O, V1, P123 2147 CASTELLANO C, 2000, PHYS REV LETT, V85, P3536 2148 DORNIC I, 2001, PHYS REV LETT, V87 2149 JENSEN HJ, 1998, SELF ORG CRITICALITY 2150 KLEMM K, 2002, CONDMAT0205188 2151 LEE BP, 1995, J STAT PHYS, V80, P971 2152 LIGGETT TM, 1985, INTERACTING PARTICLE 2153 MARRO J, 1999, NONEQUILIBRIUM PHASE 2154 PELITI L, 1985, J PHYS-PARIS, V46, P1469 2155 REDNER S, 1997, NONEQUILIBRIUM STAT 2156 STROGATZ SH, 2001, NATURE, V410, P268 2157 WATTS DJ, 1999, SMALL WORLDS DYNAMIC 2158 NR 14 2159 TC 13 2160 PU SPRINGER-VERLAG 2161 PI NEW YORK 2162 PA 175 FIFTH AVE, NEW YORK, NY 10010 USA 2163 SN 1434-6028 2164 J9 EUR PHYS J B 2165 JI Eur. Phys. J. B 2166 PD DEC 2167 PY 2002 2168 VL 30 2169 IS 3 2170 BP 399 2171 EP 406 2172 PG 8 2173 SC Physics, Condensed Matter 2174 GA 643EZ 2175 UT ISI:000180850100016 2176 ER 2177 2178 PT J 2179 AU Boguna, M 2180 Pastor-Satorras, R 2181 Vespignani, A 2182 TI Absence of epidemic threshold in scale-free networks with degree 2183 correlations 2184 SO PHYSICAL REVIEW LETTERS 2185 LA English 2186 DT Article 2187 ID COMPLEX NETWORKS; DYNAMICS 2188 AB Random scale-free networks have the peculiar property of being prone to 2189 the spreading of infections. Here we provide for the 2190 susceptible-infected-susceptible model an exact result showing that a 2191 scale-free degree distribution with diverging second moment is a 2192 sufficient condition to have null epidemic threshold in unstructured 2193 networks with either assortative or disassortative mixing. Degree 2194 correlations result therefore irrelevant for the epidemic spreading 2195 picture in these scale-free networks. The present result is related to 2196 the divergence of the average nearest neighbor's degree, enforced by 2197 the degree detailed balance condition. 2198 C1 Univ Barcelona, Dept Fis Fonamental, E-08028 Barcelona, Spain. 2199 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 2200 Univ Paris 11, CNRS, UMR 8627, Phys Theor Lab, F-91405 Orsay, France. 2201 RP Boguna, M, Univ Barcelona, Dept Fis Fonamental, Ave Diagonal 647, 2202 E-08028 Barcelona, Spain. 2203 CR ALBERT R, 2000, NATURE, V406, P378 2204 ALBERT R, 2002, REV MOD PHYS, V74, P47 2205 ANDERSON RM, 1992, INFECT DIS HUMANS 2206 BARABASI AL, 1999, SCIENCE, V286, P509 2207 BOGUNA M, 2002, PHYS REV E 2, V66 2208 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 2209 COHEN R, 2000, PHYS REV LETT, V85, P4626 2210 DOROGOVTSEV SN, 2002, ADV PHYS, V51, P1079 2211 EGUILUZ VM, 2002, PHYS REV LETT, V89 2212 GANTMACHER FR, 1974, THEORY MATRICES, V2 2213 KLEMM K, 2002, PHYS REV E 2A, V65 2214 MASLOV S, 2002, SCIENCE, V296, P910 2215 MAY RM, 2001, PHYS REV E 2, V64 2216 MORENO Y, CONDMAT0201362 2217 NEWMAN MEJ, 2002, PHYS REV LETT, V89 2218 PASTORSATORRAS R, 2001, PHYS REV E 2, V63 2219 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 2220 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 2221 PASTORSATORRAS R, 2002, HDB GRAPHS NETWORKS, P113 2222 VAZQUEZ A, 2002, PHYS REV E 2, V65 2223 VAZQUEZ A, 2003, PHYS REV E, V65 2224 VOLCHENKOV D, 2002, PHYS REV E 2, V66 2225 WARREN CP, 2002, PHYS REV E, V66 2226 WATTS DJ, 1998, NATURE, V393, P440 2227 NR 24 2228 TC 52 2229 PU AMERICAN PHYSICAL SOC 2230 PI COLLEGE PK 2231 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 2232 SN 0031-9007 2233 J9 PHYS REV LETT 2234 JI Phys. Rev. Lett. 2235 PD JAN 17 2236 PY 2003 2237 VL 90 2238 IS 2 2239 AR 028701 2240 DI ARTN 028701 2241 PG 4 2242 SC Physics, Multidisciplinary 2243 GA 636FP 2244 UT ISI:000180444200058 2245 ER 2246 2247 PT J 2248 AU Miguel, MC 2249 Vespignani, A 2250 Zaiser, M 2251 Zapperi, S 2252 TI Dislocation jamming and Andrade creep 2253 SO PHYSICAL REVIEW LETTERS 2254 LA English 2255 DT Article 2256 ID CRITICAL-DYNAMICS; SINGLE-CRYSTALS; DEFORMATION; SIMULATION; SLIP; FLOW 2257 AB We simulate the glide motion of an assembly of interacting dislocations 2258 under the action of an external shear stress and show that the 2259 associated plastic creep relaxation follows Andrade's law. Our results 2260 indicate that Andrade creep in plastically deforming crystals involves 2261 the correlated motion of dislocation structures near a dynamic 2262 transition separating a flowing from a jammed phase. Simulations in the 2263 presence of dislocation multiplication and noise confirm the robustness 2264 of this finding and highlight the importance of metastable structure 2265 formation for the relaxation process. 2266 C1 Univ Barcelona, Dipartimento Fis Fonamental, Fac Fis, E-08028 Barcelona, Spain. 2267 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 2268 Univ Edinburgh, Ctr Mat Sci & Engn, Edinburgh EH9 3JL, Midlothian, Scotland. 2269 Univ Roma La Sapienza, INFM, Unita Rome 1, I-00185 Rome, Italy. 2270 Univ Roma La Sapienza, Ctr Stat Mech & Complex, Dipartimento Fis, I-00185 Rome, Italy. 2271 RP Miguel, MC, Univ Barcelona, Dipartimento Fis Fonamental, Fac Fis, Ave 2272 Diagonal 647, E-08028 Barcelona, Spain. 2273 CR AMODEO RJ, 1990, PHYS REV B B, V41, P6958 2274 AMODEO RJ, 1990, PHYS REV B, V41, P6968 2275 ANANTHAKRISHNA G, 1999, PHYS REV E A, V60, P5455 2276 ANDRADE END, 1910, P R SOC LOND A-CONTA, V84, P1 2277 ANDRADE END, 1914, P R SOC LOND A-CONTA, V90, P329 2278 BECKER R, 1932, Z PHYS, V79, P566 2279 BENGUS VZ, 1966, PHYS STATUS SOLIDI, V14, P215 2280 COTTRELL AH, 1996, PHIL MAG LETT, V73, P35 2281 COTTRELL AH, 1996, PHIL MAG LETT, V74, P375 2282 COTTRELL AH, 1997, PHIL MAG LETT, V75, P301 2283 DANNA G, 1997, J APPL PHYS, V82, P5983 2284 DANNA G, 2000, PHYS REV LETT, V85, P4096 2285 ESSMANN U, 1979, PHIL MAG A, V40, P731 2286 FRIEDEL J, 1967, DISLOCATIONS 2287 GROMA I, 1993, PHILOS MAG A, V67, P1459 2288 GROMA I, 2000, PHYS REV LETT, V84, P1487 2289 HAHNER P, 1998, PHYS REV LETT, V81, P2470 2290 HIRTH JP, 1992, THEORY DISLOCATIONS 2291 KOCKS UF, 1975, PROGR MATERIALS SCIE, V19, P1 2292 LEPINOUX J, 1987, SCRIPTA METALL, V21, P833 2293 LIU AJ, 1998, NATURE, V396, P21 2294 MIGUEL MC, 2001, NATURE, V410, P667 2295 MOTT NF, 1953, PHILOS MAG, V44, P741 2296 NABARRO FRN, 1992, THEORY CRYSTAL DISLO 2297 NABARRO FRN, 1997, PHIL MAG LETT, V75, P227 2298 NEUHAUSER H, 1983, DISLOCATIONS SOLIDS, V6, P319 2299 SEVILLANO JG, 1991, SCRIPTA METALL MATER, V25, P355 2300 ZAPPERI S, 2001, MAT SCI ENG A-STRUCT, V309, P348 2301 NR 28 2302 TC 17 2303 PU AMERICAN PHYSICAL SOC 2304 PI COLLEGE PK 2305 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 2306 SN 0031-9007 2307 J9 PHYS REV LETT 2308 JI Phys. Rev. Lett. 2309 PD OCT 14 2310 PY 2002 2311 VL 89 2312 IS 16 2313 AR 165501 2314 DI ARTN 165501 2315 PG 4 2316 SC Physics, Multidisciplinary 2317 GA 600HJ 2318 UT ISI:000178384300025 2319 ER 2320 2321 PT J 2322 AU Leone, M 2323 Vazquez, A 2324 Vespignani, A 2325 Zecchina, R 2326 TI Ferromagnetic ordering in graphs with arbitrary degree distribution 2327 SO EUROPEAN PHYSICAL JOURNAL B 2328 LA English 2329 DT Article 2330 ID REPLICA SYMMETRY-BREAKING; MEAN-FIELD THEORY; K-SATISFIABILITY PROBLEM; 2331 LATTICE SPIN-GLASS; FINITE CONNECTIVITY; BETHE LATTICE; COMPLEX 2332 NETWORKS; DEGREE SEQUENCE; SYSTEMS; SIZE 2333 AB We present a detailed study of the phase diagram of the Ising model in 2334 random graphs with arbitrary degree distribution. By using the replica 2335 method we compute exactly the value of the critical temperature and the 2336 associated critical exponents as a function of the moments of the 2337 degree distribution. Two regimes of the degree distribution are of 2338 particular interest. In the case of a divergent second moment, the 2339 system is ferromagnetic at all temperatures. In the case of a finite 2340 second moment and a divergent fourth moment, there is a ferromagnetic 2341 transition characterized by non-trivial critical exponents. Finally, if 2342 the fourth moment is finite we recover the mean field exponents. These 2343 results are analyzed in detail for power-law distributed random graphs. 2344 C1 Scuola Int Super Studi Avanzati, I-34014 Trieste, Italy. 2345 INFM, I-34014 Trieste, Italy. 2346 Abdus Salam Int Ctr Theoret Phys, I-34014 Trieste, Italy. 2347 RP Leone, M, Scuola Int Super Studi Avanzati, Via Beirut 4, I-34014 2348 Trieste, Italy. 2349 CR AIELLO W, 2000, P 32 ANN ACM S THEOR, P171 2350 ALBERT R, 2002, REV MOD PHYS, V74, P47 2351 ALEKSIEJUK A, CONDMAT0112312 2352 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 2353 BARABASI AL, 1999, PHYSICA A, V272, P173 2354 BARABASI AL, 1999, SCIENCE, V286, P509 2355 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 2356 CARLSON JM, 1988, EUROPHYS LETT, V5, P355 2357 COHEN R, CONDMAT0202259 2358 COHEN R, 2001, PHYS REV LETT, V86, P3682 2359 DEDOMINICIS C, 1987, J PHYS A, V20, L1267 2360 DOROGOVTSEV SN, CONDMAT0106144 2361 FRANZ S, CONDMAT0103026 2362 FRANZ S, UNPUB 2363 GOLDSCHMIDT YY, 1990, J PHYS A, V23, L775 2364 KANTER I, 1987, PHYS REV LETT, V58, P164 2365 KOROGOVTSEV SN, 2002, PHYSICA A, V310, P260 2366 LEONE M, 2001, J PHYS A-MATH GEN, V34, P4615 2367 MEZARD M, 1987, EUROPHYS LETT, V3, P1067 2368 MEZARD M, 2001, EUR PHYS J B, V20, P217 2369 MOLLOY M, 1995, RANDOM STRUCT ALGOR, V6, P161 2370 MOLLOY M, 1998, COMB PROBAB COMPUT, V7, P295 2371 MONASSON R, 1996, PHYS REV LETT, V76, P3881 2372 MONASSON R, 1997, PHYS REV E, V56, P1357 2373 MONASSON R, 1998, J PHYS A-MATH GEN, V31, P513 2374 MORENO Y, 2002, EUROPHYS LETT, V57, P765 2375 NEWMAN MEJ, 2001, PHYS REV E 2, V64 2376 PASTORSATORRAS R, 2001, PHYS REV E 2, V63 2377 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 2378 RICCITERSENGHI F, 2001, PHYS REV E 2, V63 2379 RIEGER H, 1992, PHYS REV B, V45, P9772 2380 STROGATZ SH, 2001, NATURE, V410, P268 2381 THOULESS DJ, 1986, PHYS REV LETT, V56, P1082 2382 VIANA L, 1985, J PHYS C SOLID STATE, V18, P3037 2383 NR 34 2384 TC 53 2385 PU SPRINGER-VERLAG 2386 PI NEW YORK 2387 PA 175 FIFTH AVE, NEW YORK, NY 10010 USA 2388 SN 1434-6028 2389 J9 EUR PHYS J B 2390 JI Eur. Phys. J. B 2391 PD JUL 2392 PY 2002 2393 VL 28 2394 IS 2 2395 BP 191 2396 EP 197 2397 PG 7 2398 SC Physics, Condensed Matter 2399 GA 588BB 2400 UT ISI:000177679600010 2401 ER 2402 2403 PT J 2404 AU Vazquez, A 2405 Pastor-Satorras, R 2406 Vespignani, A 2407 TI Large-scale topological and dynamical properties of the Internet 2408 SO PHYSICAL REVIEW E 2409 LA English 2410 DT Article 2411 ID GROWING RANDOM NETWORKS; SMALL-WORLD NETWORKS; RANDOM GRAPHS; EVOLVING 2412 NETWORKS; COMPLEX NETWORKS; DEGREE SEQUENCE; WIDE-WEB; ATTACK; GROWTH 2413 AB We study the large-scale topological and dynamical properties of real 2414 Internet maps at the autonomous system level, collected in a 3-yr time 2415 interval. We find that the connectivity structure of the Internet 2416 presents statistical distributions settled in a well-defined stationary 2417 state. The large-scale properties are characterized by a scale-free 2418 topology consistent with previous observations. Correlation functions 2419 and clustering coefficients exhibit a remarkable structure due to the 2420 underlying hierarchical organization of the Internet. The study of the 2421 Internet time evolution shows a growth dynamics with aging features 2422 typical of recently proposed growing network models. We compare the 2423 properties of growing network models with the present real Internet 2424 data analysis. 2425 C1 SISSA, Int Sch Adv Studies, I-34014 Trieste, Italy. 2426 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 2427 Int Ctr Theoret Phys, I-34100 Trieste, Italy. 2428 RP Vazquez, A, SISSA, Int Sch Adv Studies, Via Beirut 4, I-34014 Trieste, 2429 Italy. 2430 CR ADAMIC LA, 2001, PHYS REV E 2, V64 2431 ALBERT R, 2000, NATURE, V406, P378 2432 ALBERT R, 2000, PHYS REV LETT, V85, P5234 2433 ALBERT R, 2002, REV MOD PHYS, V74, P47 2434 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 2435 BARABASI AL, 1999, PHYSICA A, V272, P173 2436 BARABASI AL, 1999, SCIENCE, V286, P509 2437 BIANCONI G, 2001, EUROPHYS LETT, V54, P436 2438 BOLLOBAS B, 1985, RANDOM GRAPHS 2439 BORNHOLDT S, 2001, PHYS REV E 2, V64 2440 CALDARELLI G, 2000, EUROPHYS LETT, V52, P386 2441 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 2442 CHESWICK B, INTERNET MAPPING PRO 2443 COHEN R, 2001, PHYS REV LETT, V86, P3682 2444 DOAR M, 1993, P IEEE INFOCOM 93 LO, P83 2445 DOROGOVTSEV SN, CONDMAT0009090 2446 DOROGOVTSEV SN, 2000, EUROPHYS LETT, V52, P33 2447 DOROGOVTSEV SN, 2000, PHYS REV LETT, V85, P4633 2448 DOROGOVTSEV SN, 2001, PHYS REV E 2, V63 2449 DOROGOVTSEV SN, 2002, ADV PHYS, V51, P1079 2450 ERDOS P, 1960, PUBL MATH I HUNG, V5, P17 2451 FALOUTSOS M, 1999, COMP COMM R, V29, P251 2452 FLOYD S, 2001, IEEE ACM T NETWORK, V9, P392 2453 GOH KI, 2001, PHYS REV LETT, V87 2454 GOH KI, 2002, PHYS REV LETT, V88 2455 GOVINDAN R, 1997, P IEEE INFOCOM, P850 2456 GOVINDAN R, 2000, P IEEE INFOCOM, V3, P1371 2457 HUBERMAN BA, 1999, NATURE, V401, P131 2458 JEONG H, CONDMAT0104131 2459 KRAPIVSKY PL, 2000, PHYS REV LETT, V85, P4629 2460 KRAPIVSKY PL, 2001, PHYS REV E 2, V63 2461 MEDINA A, 2000, COMPUT COMMUN REV, V30, P18 2462 MOLLOY M, 1995, RANDOM STRUCT ALGOR, V6, P161 2463 MOLLOY M, 1998, COMB PROBAB COMPUT, V7, P295 2464 NEWMAN MEJ, 2001, PHYS REV E 2, V64 2465 NEWMAN MEJ, 2001, PHYS REV E 2, V64 2466 PANSIOT JJ, 1998, ACM COMPUTER COMMUNI, V28, P41 2467 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 2468 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 2469 PUNIYANI AR, CONDMAT0107212 2470 SIMON HA, 1955, BIOMETRIKA, V42, P425 2471 STROGATZ SH, 2001, NATURE, V410, P268 2472 VUKADINOVIC D, 2002, LECT NOTES COMPUTER 2473 WATTS DJ, 1998, NATURE, V393, P440 2474 WATTS DJ, 1999, SMALL WORLDS DYNAMIC 2475 YOOK SH, CONDMAT0107417 2476 ZEGURA EW, 1997, IEEE ACM T NETWORK, V5, P770 2477 NR 47 2478 TC 123 2479 PU AMERICAN PHYSICAL SOC 2480 PI COLLEGE PK 2481 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 2482 SN 1063-651X 2483 J9 PHYS REV E 2484 JI Phys. Rev. E 2485 PD JUN 2486 PY 2002 2487 VL 65 2488 IS 6 2489 PN Part 2 2490 AR 066130 2491 DI ARTN 066130 2492 PG 12 2493 SC Physics, Fluids & Plasmas; Physics, Mathematical 2494 GA 572FM 2495 UT ISI:000176762900037 2496 ER 2497 2498 PT J 2499 AU Moreno, Y 2500 Pastor-Satorras, R 2501 Vespignani, A 2502 TI Epidemic outbreaks in complex heterogeneous networks 2503 SO EUROPEAN PHYSICAL JOURNAL B 2504 LA English 2505 DT Article 2506 ID SMALL-WORLD NETWORKS; WIDE-WEB; TRANSMISSION DYNAMICS; INTERNET; 2507 PERCOLATION; TOPOLOGY; GRAPHS; MODEL; HIV 2508 AB We present a detailed analytical and numerical study for the spreading 2509 of infections with acquired immunity in complex population networks. We 2510 show that the large connectivity fluctuations usually found in these 2511 networks strengthen considerably the incidence of epidemic outbreaks. 2512 Scale-free networks, which are characterized by diverging connectivity 2513 fluctuations in the limit of a very large number of nodes, exhibit the 2514 lack of an epidemic threshold and always show a finite fraction of 2515 infected individuals. This particular weakness, observed also in models 2516 without immunity, defines a new epidemiological framework characterized 2517 by a highly heterogeneous response of the system to the introduction of 2518 infected individuals with different connectivity. The understanding of 2519 epidemics in complex networks might deliver new insights in the spread 2520 of information and diseases in biological and technological networks 2521 that often appear to be characterized by complex heterogeneous 2522 architectures. 2523 C1 Abdus Salam Ctr Theoret Phys, I-34100 Trieste, Italy. 2524 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 2525 RP Moreno, Y, Abdus Salam Ctr Theoret Phys, POB 586, I-34100 Trieste, 2526 Italy. 2527 CR ABRAMOWITZ M, 1972, HDB MATH FUNCTIONS 2528 ALBERT R, 1999, NATURE, V401, P130 2529 ALBERT R, 2000, NATURE, V409, P542 2530 ALBERT R, 2000, PHYS REV LETT, V85, P5234 2531 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 2532 ANDERSON RM, 1992, INFECT DIS HUMANS 2533 BARABASI AL, 1999, SCIENCE, V286, P509 2534 BARRAT A, 2000, EUR PHYS J B, V13, P547 2535 BARTHELEMY M, 1999, PHYS REV LETT, V82, P3180 2536 BORNHOLDT S, 2001, PHYS REV E 2, V64 2537 CALDARELLI G, 2000, EUROPHYS LETT, V52, P386 2538 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 2539 COHEN R, 2001, PHYS REV LETT, V86, P3682 2540 DEMENEZES MA, 2000, EUROPHYS LETT, V50, P574 2541 DOROGOVTSEV SN, 2000, PHYS REV LETT, V85, P4633 2542 DOROGOVTSEV SN, 2001, CONDMAT0106144 2543 ERDOS P, 1960, PUBL MATH I HUNG, V5, P17 2544 FALOUTSOS M, 1999, COMP COMM R, V29, P251 2545 HETHCOTE HW, 1978, THEORETICAL POPULATI, V14, P338 2546 HETHCOTE HW, 1984, LECT NOTES BIOMATHS, V56, P1 2547 KRAPIVSKY PL, 2000, PHYS REV LETT, V85, P4629 2548 KUPERMAN M, 2001, PHYS REV LETT, V86, P2909 2549 LILJEROS F, 2001, NATURE, V411, P907 2550 LLOYD AL, 2001, SCIENCE, V292, P1316 2551 MARRO J, 1999, NONEQUILIBRIUM PHASE 2552 MAY RM, 1984, MATH BIOSCI, V72, P83 2553 MAY RM, 1987, NATURE, V326, P137 2554 MAY RM, 1988, PHIL T R SOC LOND B, V321, P565 2555 MAY RM, 2001, PHYS REV E 2, V64 2556 MOORE C, 2000, PHYS REV E B, V61, P5678 2557 MURRAY JD, 1993, MATH BIOL 2558 NEWMAN MEJ, 1999, PHYS REV E, V60, P5678 2559 PASTORSATORRAS FR, 2001, PHYS REV LETT, V8725, P8701 2560 PASTORSATORRAS FR, 2002, PHYS REV E, V6503, P5108 2561 PASTORSATORRAS R, 2001, PHYS REV E 2, V63 2562 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 2563 PASTORSATORRAS R, 2002, PHYS REV E 2A, V65 2564 SIMON HA, 1955, BIOMETRIKA, V42, P425 2565 STROGATZ SH, 2001, NATURE, V410, P268 2566 TADIC B, 2001, PHYSICA A, V293, P273 2567 WATTS DJ, 1998, NATURE, V393, P440 2568 WATTS DJ, 1999, SMALL WORLDS DYNAMIC 2569 NR 42 2570 TC 69 2571 PU SPRINGER-VERLAG 2572 PI NEW YORK 2573 PA 175 FIFTH AVE, NEW YORK, NY 10010 USA 2574 SN 1434-6028 2575 J9 EUR PHYS J B 2576 JI Eur. Phys. J. B 2577 PD APR 2578 PY 2002 2579 VL 26 2580 IS 4 2581 BP 521 2582 EP 529 2583 PG 9 2584 SC Physics, Condensed Matter 2585 GA 556QC 2586 UT ISI:000175859600017 2587 ER 2588 2589 PT J 2590 AU Pastor-Satorras, R 2591 Vespignani, A 2592 TI Epidemic dynamics in finite size scale-free networks 2593 SO PHYSICAL REVIEW E 2594 LA English 2595 DT Article 2596 ID SMALL-WORLD NETWORKS; INTERNET 2597 AB Many real networks present a bounded scale-free behavior with a 2598 connectivity cutoff due to physical constraints or a finite network 2599 size. We study epidemic dynamics in bounded scale-free networks with 2600 soft and hard connectivity cutoffs. The finite size effects introduced 2601 by the cutoff induce an epidemic threshold that approaches zero at 2602 increasing sizes. The induced epidemic threshold is very small even at 2603 a relatively small cutoff, showing that the neglection of connectivity 2604 fluctuations in bounded scale-free networks leads to a strong 2605 overestimation of the epidemic threshold. We provide the expression for 2606 the infection prevalence and discuss its finite size corrections. The 2607 present paper shows that the highly heterogeneous nature of scale-free 2608 networks does not allow the use of homogeneous approximations even for 2609 systems of a relatively small number of nodes. 2610 C1 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 2611 RP Pastor-Satorras, R, Univ Politecn Catalunya, Dept Fis & Engn Nucl, 2612 Campus Nord B4, ES-08034 Barcelona, Spain. 2613 CR ABRAMOWITZ M, 1972, HDB MATH FUNCTIONS 2614 ALBERT R, 1999, NATURE, V401, P130 2615 ALBERT R, 2002, REV MOD PHYS, V74, P47 2616 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 2617 ANDERSON RM, 1992, INFECT DIS HUMANS 2618 BARABASI AL, 1999, SCIENCE, V286, P509 2619 CALDARELLI G, 2000, EUROPHYS LETT, V52, P386 2620 DEZSO Z, CONDMAT0107420 2621 DIEKMANN O, 2000, MATH EPIDEMIOLOGY IN 2622 DOROGOVTSEV SN, CONDMAT0106144 2623 FALOUTSOS M, 1999, COMP COMM R, V29, P251 2624 HETHCOTE HW, 1984, LECT NOTES BIOMATHS, V56, P1 2625 LILJEROS F, 2001, NATURE, V411, P907 2626 MARRO J, 1999, NONEQULIBRIUM PHASE 2627 MAY RM, 2001, PHYS REV E 2, V64 2628 MORENO Y, CONDMAT0107267 2629 PASTORSATORRAS R, CONDMAT0107066 2630 PASTORSATORRAS R, 2001, PHYS REV E 2, V63 2631 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 2632 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 2633 STROGATZ SH, 2001, NATURE, V410, P268 2634 WATTS DJ, 1998, NATURE, V393, P440 2635 NR 22 2636 TC 44 2637 PU AMERICAN PHYSICAL SOC 2638 PI COLLEGE PK 2639 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 2640 SN 1063-651X 2641 J9 PHYS REV E 2642 JI Phys. Rev. E 2643 PD MAR 2644 PY 2002 2645 VL 65 2646 IS 3 2647 PN Part 2A 2648 AR 035108 2649 DI ARTN 035108 2650 PG 4 2651 SC Physics, Fluids & Plasmas; Physics, Mathematical 2652 GA 533UN 2653 UT ISI:000174548900008 2654 ER 2655 2656 PT J 2657 AU Pastor-Satorras, R 2658 Vespignani, A 2659 TI Immunization of complex networks 2660 SO PHYSICAL REVIEW E 2661 LA English 2662 DT Article 2663 ID SMALL-WORLD NETWORKS; INTERNET; DYNAMICS 2664 AB Complex networks such as the sexual partnership web or the Internet 2665 often show a high degree of redundancy and heterogeneity in their 2666 connectivity properties. This peculiar connectivity provides an ideal 2667 environment for the spreading of infective agents. Here we show that 2668 the random uniform immunization of individuals does not lead to the 2669 eradication of infections in all complex networks. Namely, networks 2670 with scale-free properties do not acquire global immunity from major 2671 epidemic outbreaks even in the presence of unrealistically high 2672 densities of randomly immunized individuals. The absence of any 2673 critical immunization threshold is due to the unbounded connectivity 2674 fluctuations of scale-free networks. Successful immunization strategies 2675 can be developed only by taking into account the inhomogeneous 2676 connectivity properties of scale-free networks. In particular, targeted 2677 immunization schemes, based on the nodes' connectivity hierarchy, 2678 sharply lower the network's vulnerability to epidemic attacks. 2679 C1 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 2680 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 2681 RP Pastor-Satorras, R, Univ Politecn Catalunya, Dept Fis & Engn Nucl, 2682 Campus Nord,Modul B4, ES-08034 Barcelona, Spain. 2683 CR ALBERT R, 1999, NATURE, V401, P130 2684 ALBERT R, 2000, NATURE, V406, P378 2685 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 2686 ANDERSON RM, 1992, INFECT DIS HUMANS 2687 BARABASI AL, 1999, PHYSICA A, V272, P173 2688 BARABASI AL, 1999, SCIENCE, V286, P509 2689 BARRAT A, 2000, EUR PHYS J B, V13, P547 2690 BELLOVIN SM, 1993, COMPUT COMMUN, V23, P26 2691 CALDARELLI G, 2000, EUROPHYS LETT, V52, P386 2692 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 2693 COHEN R, 2001, PHYS REV LETT, V86, P3682 2694 DEZSO Z, CONDMAT0107420 2695 DIEKMANN O, 2000, MATH EPIDEMIOLOGY IN 2696 DOROGOVTSEV SN, CONDMAT0106144 2697 DOROGOVTSEV SN, 2000, PHYS REV LETT, V85, P4633 2698 ERDOS P, 1960, PUBL MATH I HUNG, V5, P17 2699 FALOUTSOS M, 1999, COMP COMM R, V29, P251 2700 HETHCOTE HW, 1984, LECT NOTES BIOMATHS, V56, P1 2701 KEPHART JO, 1993, IEEE SPECTRUM, V30, P20 2702 LILJEROS F, 2001, NATURE, V411, P907 2703 LLOYD AL, 2001, SCIENCE, V292, P1316 2704 MARRO J, 1999, NONEQUILIBRIUM PHASE 2705 MAY RM, 1987, NATURE, V326, P137 2706 MAY RM, 2001, PHYS REV E 2, V64 2707 PASTORSATORRAS R, UNPUB 2708 PASTORSATORRAS R, 2001, PHYS REV E 2, V63 2709 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 2710 PASTORSATORRAS R, 2001, PHYS REV LETT, V87 2711 STROGATZ SH, 2001, NATURE, V410, P268 2712 WATTS DJ, 1998, NATURE, V393, P440 2713 NR 30 2714 TC 76 2715 PU AMERICAN PHYSICAL SOC 2716 PI COLLEGE PK 2717 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 2718 SN 1063-651X 2719 J9 PHYS REV E 2720 JI Phys. Rev. E 2721 PD MAR 2722 PY 2002 2723 VL 65 2724 IS 3 2725 PN Part 2A 2726 AR 036104 2727 DI ARTN 036104 2728 PG 8 2729 SC Physics, Fluids & Plasmas; Physics, Mathematical 2730 GA 533UN 2731 UT ISI:000174548900027 2732 ER 2733 2734 PT J 2735 AU Pastor-Satorras, R 2736 Vazquez, A 2737 Vespignani, A 2738 TI Dynamical and correlation properties of the Internet 2739 SO PHYSICAL REVIEW LETTERS 2740 LA English 2741 DT Article 2742 ID SMALL-WORLD NETWORKS; TOPOLOGY 2743 AB The description of the Internet topology is an important open problem, 2744 recently tackled with the introduction of scale-free networks. We focus 2745 on the topological and dynamical properties of real Internet maps in a 2746 three-year time interval. We study higher order correlation functions 2747 as well as the dynamics of several quantities. We find that the 2748 Internet is characterized by nontrivial correlations among nodes and 2749 different dynamical regimes. We point out the importance of node 2750 hierarchy and aging in the Internet structure and growth. Our results 2751 provide hints towards the realistic modeling of the Internet evolution. 2752 C1 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 2753 Scuola Int Super Studi Avanzati, SISSA, I-34014 Trieste, Italy. 2754 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 2755 RP Pastor-Satorras, R, Univ Politecn Catalunya, Dept Fis & Engn Nucl, 2756 Campus Nord,Modul B4, ES-08034 Barcelona, Spain. 2757 CR ALBERT R, 2000, NATURE, V406, P378 2758 ALBERT R, 2000, PHYS REV LETT, V85, P5234 2759 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 2760 BARABASI AL, 1999, PHYSICA A, V272, P173 2761 BARABASI AL, 1999, SCIENCE, V286, P509 2762 BIANCONI G, 2001, EUROPHYS LETT, V54, P436 2763 CALDARELLI G, 2000, EUROPHYS LETT, V52, P386 2764 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 2765 CHESWICK B, INTENET MAPPING PROJ 2766 COHEN R, 2001, PHYS REV LETT, V86, P3682 2767 DOROGOVTSEV SN, 2000, EUROPHYS LETT, V52, P33 2768 DOROGOVTSEV SN, 2000, PHYS REV LETT, V85, P4633 2769 DOROGOVTSEV SN, 2001, PHYS REV E, V63, P2510 2770 FALOUTSOS M, 1999, COMP COMM R, V29, P251 2771 JEONG H, CONDMAT0104131 2772 KRAPIVSKY PL, 2000, PHYS REV LETT, V85, P4629 2773 KRAPIVSKY PL, 2001, PHYS REV E, V63, P6612 2774 MEDINA A, 2000, COMPUT COMMUN REV, V30, P18 2775 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 2776 STROGATZ SH, 2001, NATURE, V410, P268 2777 WATTS DJ, 1998, NATURE, V393, P440 2778 ZEGURA EW, 1997, IEEE ACM T NETWORK, V5, P770 2779 NR 22 2780 TC 224 2781 PU AMERICAN PHYSICAL SOC 2782 PI COLLEGE PK 2783 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 2784 SN 0031-9007 2785 J9 PHYS REV LETT 2786 JI Phys. Rev. Lett. 2787 PD DEC 17 2788 PY 2001 2789 VL 87 2790 IS 25 2791 AR 258701 2792 DI ARTN 258701 2793 PG 4 2794 SC Physics, Multidisciplinary 2795 GA 504PZ 2796 UT ISI:000172866200061 2797 ER 2798 2799 PT J 2800 AU Dickman, R 2801 Alava, M 2802 Munoz, MA 2803 Peltola, J 2804 Vespignani, A 2805 Zapperi, S 2806 TI Critical behavior of a one-dimensional fixed-energy stochastic sandpile 2807 SO PHYSICAL REVIEW E 2808 LA English 2809 DT Article 2810 ID SELF-ORGANIZED CRITICALITY; ABELIAN SANDPILE; CRITICAL EXPONENTS; 2811 PHASE-TRANSITIONS; ABSORBING STATES; FIELD-THEORY; MODEL; UNIVERSALITY; 2812 AVALANCHES; EVENTS 2813 AB We study a one-dimensional fixed-energy version (that is, with no input 2814 or loss of particles) of Manna's stochastic sandpile model, The system 2815 has a continuous transition to an absorbing state at a critical value 2816 of the particle density, and exhibits the hallmarks of an 2817 absorbing-state phase transition, including finite-size scaling. 2818 Critical exponents are obtained from extensive simulations, which treat 2819 stationary and transient properties, and an associated interface 2820 representation. These exponents characterize the universality class of 2821 an absorbing-state phase transition with a static conserved density in 2822 one dimension; they differ from those expected at a linear-interface 2823 depinning transition in a medium with point disorder, and from those of 2824 directed percolation. 2825 C1 Univ Fed Minas Gerais, ICEx, Dept Fis, BR-30161970 Belo Horizonte, MG, Brazil. 2826 Helsinki Univ Technol, Phys Lab, HUT-02105 Helsinki, Finland. 2827 Inst Carlos I Theoret & Computat Phys, Granada 18071, Spain. 2828 Dept Electromagnetismo & Fis Mat, Granada 18071, Spain. 2829 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 2830 Univ Roma La Sapienza, Dipartimento Fis Enrico Fermi, INFM, I-00185 Rome, Italy. 2831 RP Dickman, R, Univ Fed Minas Gerais, ICEx, Dept Fis, Caixa Postal 702, 2832 BR-30161970 Belo Horizonte, MG, Brazil. 2833 CR ALAVA M, CONDMAT0002406 2834 ALAVA M, 2001, EUROPHYS LETT, V53, P569 2835 BAK P, 1987, PHYS REV LETT, V59, P381 2836 BAK P, 1988, PHYS REV A, V38, P364 2837 BARABASI AL, 1995, FRACTAL CONCEPTS SUR 2838 CHESSA A, 1998, PHYS REV LETT, V80, P4217 2839 DEMENECH M, 1998, PHYS REV E A, V58, R2677 2840 DHAR D, 1999, PHYSICA A, V263, P4 2841 DICKMAN R, CONDMAT9910454 2842 DICKMAN R, UNPUB 2843 DICKMAN R, 1998, PHYS REV E A, V57, P5095 2844 DICKMAN R, 2000, BRAZ J PHYS, V30, P27 2845 DICKMAN R, 2000, PHYS REV E A, V62, P7632 2846 DROSSEL B, 2000, PHYS REV E, V61, R2168 2847 FISHER ME, 1971, FENOMINI CRITICI 2848 FISHER ME, 1972, PHYS REV LETT, V28, P1516 2849 FISHER ME, 1988, FINITE SIZE SCALING 2850 GRASSBERGER P, 1982, Z PHYS B, V47, P465 2851 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 2852 HALPINHEALY T, 1995, PHYS REP, V254, P215 2853 IVASHKEVICH EV, 1994, J PHYS A-MATH GEN, V27, P3643 2854 IVASHKEVICH EV, 1994, PHYSICA A, V209, P347 2855 JANSSEN HK, 1981, Z PHYS, V42, P141 2856 JANSSEN HK, 1985, Z PHYS B CON MAT, V58, P311 2857 KADANOFF LP, 1989, PHYS REV A, V39, P6524 2858 KARDAR M, 1998, PHYS REP, V301, P85 2859 LESCHHORN H, 1993, PHYSICA A, V195, P324 2860 LOPEZ JM, 1997, PHYS REV E, V56, P3993 2861 LOPEZ JM, 1999, PHYS REV LETT, V83, P4594 2862 MANNA SS, 1990, J STAT PHYS, V59, P509 2863 MANNA SS, 1991, J PHYS A, V24, L363 2864 MARRO J, 1999, NONEQUILIBRIUM PHASE 2865 MONTAKHAB A, 1998, PHYS REV E A, V58, P5608 2866 MUNOZ MA, 1999, PHYS REV E B, V59, P6175 2867 MUNOZ MA, 2001, P 6 GRAN SEM COMP PH 2868 PACZUSKI M, 1994, EUROPHYS LETT, V27, P97 2869 PACZUSKI M, 1994, EUROPHYS LETT, V28, P295 2870 PARISI G, 1991, EUROPHYS LETT, V16, P321 2871 PARISI G, 1991, PHYSICA A, V179, P16 2872 PASTORSATORRAS R, 2000, PHYS REV E A, V62, R5875 2873 PRIEZZHEV VB, 1994, J STAT PHYS, V74, P955 2874 ROSSI M, 2000, PHYS REV LETT, V85, P1803 2875 TANG C, 1988, PHYS REV LETT, V60, P2347 2876 TEBALDI C, 1999, PHYS REV LETT, V83, P3952 2877 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 2878 VESPIGNANI A, 1998, PHYS REV E, V57, P6345 2879 VESPIGNANI A, 1998, PHYS REV LETT, V81, P5676 2880 VESPIGNANI A, 2000, PHYS REV E A, V62, P4564 2881 NR 48 2882 TC 26 2883 PU AMERICAN PHYSICAL SOC 2884 PI COLLEGE PK 2885 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 2886 SN 1063-651X 2887 J9 PHYS REV E 2888 JI Phys. Rev. E 2889 PD NOV 2890 PY 2001 2891 VL 64 2892 IS 5 2893 PN Part 2 2894 AR 056104 2895 DI ARTN 056104 2896 PG 7 2897 SC Physics, Fluids & Plasmas; Physics, Mathematical 2898 GA 496QH 2899 UT ISI:000172407100015 2900 ER 2901 2902 PT J 2903 AU Pastor-Satorras, R 2904 Vespignani, A 2905 TI Epidemic dynamics and endemic states in complex networks 2906 SO PHYSICAL REVIEW E 2907 LA English 2908 DT Article 2909 ID SMALL-WORLD NETWORKS; WIDE-WEB; INTERNET; TOPOLOGY 2910 AB We study by analytical methods and large scale simulations a dynamical 2911 model for the spreading of epidemics in complex networks. in networks 2912 with exponentially bounded connectivity we recover the usual epidemic 2913 behavior with a threshold defining a critical point below that the 2914 infection prevalence is null. On the contrary, on a wide range of 2915 scale-free networks we observe the absence of an epidemic threshold and 2916 its associated critical behavior. This implies that scale-free networks 2917 are prone to the spreading and the persistence of infections whatever 2918 spreading rate the epidemic agents might possess. These results can 2919 help understanding. computer virus epidemics and other spreading 2920 phenomena on communication and social networks. 2921 C1 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 2922 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 2923 RP Pastor-Satorras, R, Univ Politecn Catalunya, Dept Fis & Engn Nucl, 2924 Campus Nord,Modul B4, ES-08034 Barcelona, Spain. 2925 CR ABRAMOWITZ M, 1972, HDB MATH FUNCTIONS 2926 ABRAMSON G, NLNAO0010012 2927 ALBERT R, 1999, NATURE, V401, P130 2928 ALBERT R, 2000, PHYS REV LETT, V85, P5234 2929 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 2930 BAILEY NTJ, 1975, MATH THEORY INFECT D 2931 BARABASI AL, 1999, PHYSICA A, V272, P173 2932 BARABASI AL, 1999, SCIENCE, V286, P509 2933 BARRAT A, CONDMAT9903323 2934 BARRAT A, 2000, EUR PHYS J B, V13, P547 2935 BARTHELEMY M, 1999, PHYS REV LETT, V82, P3180 2936 BOLLOBAS B, 1985, RANDOM GRAPHS 2937 BORNHOLDT S, CONDMAT0008465 2938 CALDARELLI G, 2000, EUROPHYS LETT, V52, P386 2939 CALLAWAY DS, 2000, PHYS REV LETT, V85, P5468 2940 COHEN R, 2000, PHYS REV LETT, V85, P4626 2941 DEMENEZES MA, 2000, EUROPHYS LETT, V50, P574 2942 DOROGOVTSEV SN, CONDMAT0011115 2943 ERDOS P, 1960, PUBL MATH I HUNG, V5, P17 2944 FALOUTSOS M, 1999, COMP COMM R, V29, P251 2945 HILL MK, 1997, UNDERSTANDING ENV PO 2946 HUBERMAN BA, 1999, NATURE, V401, P131 2947 JEONG H, 2000, NATURE, V407, P651 2948 KEPHART JO, 1993, IEEE SPECTRUM, V30, P20 2949 KEPHART JO, 1997, SCI AM, V277, P56 2950 KRAPIVSKY PL, 2000, PHYS REV LETT, V85, P4629 2951 MARRO J, 1999, NONEQUILIBRIUM PHASE 2952 MEDINA A, 2000, COMPUT COMMUN REV, V30, P18 2953 MONTOYA JM, CONDMAT0011195 2954 MOORE C, 2000, PHYS REV E B, V61, P5678 2955 MURRAY JD, 1993, MATH BIOL 2956 NEWMAN MEJ, 1999, PHYS REV E, V60, P5678 2957 PASTORSATORRAS R, IN PRESS PHYS REV LE 2958 PASTORSATORRAS R, 2001, PHYS REV LETT, V86, P3200 2959 SIMON HA, 1955, BIOMETRIKA, V42, P425 2960 TADIC B, 2001, PHYSICA A, V293, P273 2961 WASSERMAN S, 1994, SOCIAL NETWORK ANAL 2962 WATTS DJ, 1998, NATURE, V393, P440 2963 WATTS DJ, 1999, SMALL WORLDS DYNAMIC 2964 WENG GZ, 1999, SCIENCE, V284, P92 2965 NR 40 2966 TC 164 2967 PU AMERICAN PHYSICAL SOC 2968 PI COLLEGE PK 2969 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 2970 SN 1063-651X 2971 J9 PHYS REV E 2972 JI Phys. Rev. E 2973 PD JUN 2974 PY 2001 2975 VL 6306 2976 IS 6 2977 PN Part 2 2978 AR 066117 2979 DI ARTN 066117 2980 PG 8 2981 SC Physics, Fluids & Plasmas; Physics, Mathematical 2982 GA 442KU 2983 UT ISI:000169285300028 2984 ER 2985 2986 PT J 2987 AU Miguel, MC 2988 Vespignani, A 2989 Zapperi, S 2990 Weiss, J 2991 Grasso, JR 2992 TI Complexity in dislocation dynamics: model 2993 SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES 2994 MICROSTRUCTURE AND PROCESSING 2995 LA English 2996 DT Article 2997 DE dislocations; statistical modelling; fluctuations; ice single crystal 2998 ID SELF-ORGANIZED CRITICALITY; ACOUSTIC-EMISSION; DEFORMATION 2999 AB We propose a numerical model to study the viscoplastic deformation of 3000 ice single crystals. We consider long-range elastic interactions among 3001 dislocations, the possibility of mutual annihilation, and a 3002 multiplication mechanism representing the activation of Frank-Read 3003 sources due to dislocation pinning. The overdamped equations of motion 3004 for a collection of dislocations are integrated numerically using 3005 different externally applied stresses. Using this approach we analyze 3006 the avalanche-like rearrangements of dislocations during the dynamic 3007 evolution. We observe a power law distribution of avalanche sizes which 3008 we compare with acoustic emission experiments in ice single crystals 3009 under creep deformation. We emphasize the connections of our model with 3010 nonequilibrium phase transitions and critical phenomena. (C) 2001 3011 Elsevier Science B.V. All rights reserved. 3012 C1 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 3013 Univ La Sapienza, INFM, I-00185 Rome, Italy. 3014 Lab Glaciol & Geophys Environm, CNRS, F-38402 St Martin Dheres, France. 3015 LGIT, F-38041 Grenoble 9, France. 3016 RP Miguel, MC, Univ Barcelona, Dept Fis Fonamental, Fac Fis, Diagonal 647, 3017 E-08028 Barcelona, Spain. 3018 CR AMODEO RJ, 1990, PHYS REV B B, V41, P6958 3019 BAK P, 1987, PHYS REV LETT, V59, P381 3020 BAKO B, 1999, PHYS REV B, V60, P122 3021 BERTOTTI G, 1994, J APPL PHYS, V75, P5490 3022 DICKMAN R, 2000, BRAZ J PHYS, V30, P27 3023 DOMB C, 1972, PHASE TRANSITION CRI, V1 3024 FIELD S, 1995, PHYS REV LETT, V74, P1206 3025 FOURNET R, 1996, PHYS REV B, V53, P6283 3026 GARCIMARTIN A, 1997, PHYS REV LETT, V79, P3202 3027 HAHNER P, 1998, PHYS REV LETT, V81, P2470 3028 HIRTH JP, 1992, THEORY DISLOCATIONS 3029 MIGUEL MC, UNPUB 3030 NABARRO FRN, 1992, THEORY CRYSTAL DISLO 3031 PETRI A, 1994, PHYS REV LETT, V73, P3423 3032 VESPIGNANI A, 1998, PHYS REV E, V57, P6345 3033 WEISS J, 1997, J PHYS CHEM B, V101, P6113 3034 WEISS J, 2000, J GEOPHYS RES-SOL EA, V105, P433 3035 WEISS J, 2001, MAT SCI ENG A-STRUCT, V309, P360 3036 NR 18 3037 TC 9 3038 PU ELSEVIER SCIENCE SA 3039 PI LAUSANNE 3040 PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND 3041 SN 0921-5093 3042 J9 MATER SCI ENG A-STRUCT MATER 3043 JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. 3044 PD JUL 15 3045 PY 2001 3046 VL 309 3047 SI Sp. Iss. SI 3048 BP 324 3049 EP 327 3050 PG 4 3051 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary 3052 GA 438GE 3053 UT ISI:000169044600066 3054 ER 3055 3056 PT J 3057 AU Weiss, J 3058 Grasso, JR 3059 Miguel, MC 3060 Vespignani, A 3061 Zapperi, S 3062 TI Complexity in dislocation dynamics: experiments 3063 SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES 3064 MICROSTRUCTURE AND PROCESSING 3065 LA English 3066 DT Article 3067 DE dislocation; acoustic emission; avalanches; critical phenomena; ice 3068 ID ACOUSTIC-EMISSION; SINGLE-CRYSTALS; DEFORMATION; ICE 3069 AB We present a statistical analysis of the acoustic emissions induced by 3070 dislocation motion during the creep of ice single crystals. The 3071 recorded acoustic waves provide an indirect measure of the inelastic 3072 energy dissipated during dislocation motion. Compression and torsion 3073 creep experiments indicate that viscoplastic deformation, even in the 3074 steady-state (secondary creep), is a complex and inhomogeneous process 3075 characterized by avalanches in the motion of dislocations. The 3076 distribution of avalanche sizes, identified with the acoustic wave 3077 amplitude (or the acoustic wave energy), is found to follow a power law 3078 with a cutoff at large amplitudes which depends on the creep stage 3079 (primary, secondary, tertiary). These results suggest that viscoplastic 3080 deformation in ice and possibly in other materials could be described 3081 in the framework of non-equilibrium critical phenomena. (C) 2001 3082 Elsevier Science B.V. All rights reserved. 3083 C1 Lab Glaciol & Geophys Environm, CNRS, F-38402 St Martin Dheres, France. 3084 LGIT, F-38041 Grenoble 9, France. 3085 Univ Barcelona, Fac Fis, E-08028 Barcelona, Spain. 3086 Abdus Salam ICTP, I-34100 Trieste, Italy. 3087 Univ La Sapienza, INFM, I-00185 Rome, Italy. 3088 RP Weiss, J, Lab Glaciol & Geophys Environm, CNRS, BP 96,54 Rue Moliere, 3089 F-38402 St Martin Dheres, France. 3090 CR ANANTHAKRISHNA G, 1999, PHYS REV E A, V60, P5455 3091 ASHBY MF, 1972, ACTA METALL, V20, P887 3092 ESHELBY JD, 1962, P ROY SOC LOND A MAT, V266, P222 3093 FRIEDEL J, 1964, DISLOCATIONS 3094 GROMA I, 1999, MODEL SIMUL MATER SC, V7, P795 3095 KIESEWETTER N, 1976, PHYS STATUS SOLIDI, V38, P569 3096 LEPINOUX J, 1987, SCRIPTA METALL, V21, P833 3097 MALEN K, 1974, PHYS STATUS SOLIDI B, V61, P637 3098 NEUHAUSER H, 1983, DISLOCATIONS SOLIDS, V6, P319 3099 ROUBY D, 1983, PHILOS MAG A, V47, P671 3100 THIBERT E, 1997, J PHYS CHEM B, V101, P3554 3101 WEISS J, 1997, J PHYS CHEM B, V101, P6113 3102 WEISS J, 2000, J GEOPHYS RES-SOL EA, V105, P433 3103 NR 13 3104 TC 12 3105 PU ELSEVIER SCIENCE SA 3106 PI LAUSANNE 3107 PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND 3108 SN 0921-5093 3109 J9 MATER SCI ENG A-STRUCT MATER 3110 JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. 3111 PD JUL 15 3112 PY 2001 3113 VL 309 3114 SI Sp. Iss. SI 3115 BP 360 3116 EP 364 3117 PG 5 3118 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary 3119 GA 438GE 3120 UT ISI:000169044600075 3121 ER 3122 3123 PT J 3124 AU Pastor-Satorras, R 3125 Vespignani, A 3126 TI Reaction-diffusion system with self-organized critical behavior 3127 SO EUROPEAN PHYSICAL JOURNAL B 3128 LA English 3129 DT Article 3130 ID ABSORBING PHASE-TRANSITIONS; ABELIAN SANDPILE; CONSERVED FIELD; MODELS; 3131 EVENTS 3132 AB We describe the construction of a conserved reaction-diffusion system 3133 that exhibits self-organized critical (avalanche-like) behavior under 3134 the action of a slow addition of particles. The model provides an 3135 illustration of the general mechanism to generate self-organized 3136 criticality in conserving systems. Extensive simulations in d = 2 and 3 3137 reveal critical exponents compatible with the universality class of the 3138 stochastic Manna sandpile model. 3139 C1 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 3140 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 3141 RP Pastor-Satorras, R, Univ Politecn Catalunya, Dept Fis & Engn Nucl, 3142 Campus Nord,Modul B4, ES-08034 Barcelona, Spain. 3143 CR BAK P, 1987, PHYS REV LETT, V59, P381 3144 BAK P, 1993, PHYS REV LETT, V71, P4083 3145 CARDY JL, 1988, CURRENT PHYSICS SOUR, V2 3146 CHESSA A, 1999, COMPUT PHYS COMMUN, V121, P299 3147 DEMENECH M, 1998, PHYS REV E A, V58, R2677 3148 DHAR D, 1999, PHYSICA A, V263, P4 3149 DICKMAN R, 1998, PHYS REV E A, V57, P5095 3150 DICKMAN R, 2000, BRAZ J PHYS, V30, P27 3151 DROSSEL B, 1992, PHYS REV LETT, V69, P1629 3152 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 3153 JENSEN HJ, 1998, SELFORGANIZED CRITIC 3154 LUBECK S, 2000, PHYS REV E, V61, P204 3155 MANNA SS, 1991, J PHYS A, V24, L363 3156 MILSHTEIN E, 1998, PHYS REV E, V58, P303 3157 NAKANISHI K, 1997, PHYS REV E, V55, P4012 3158 PASTORSATORRAS R, 2000, PHYS REV E A, V62, R5875 3159 ROSSI M, 2000, PHYS REV LETT, V85, P1803 3160 TEBALDI C, 1999, PHYS REV LETT, V83, P3952 3161 VANWIJLAND F, 1998, PHYSICA A, V251, P179 3162 VESPIGNANI A, 2000, PHYS REV E A, V62, P4564 3163 ZHANG YC, 1989, PHYS REV LETT, V63, P470 3164 NR 21 3165 TC 6 3166 PU SPRINGER-VERLAG 3167 PI NEW YORK 3168 PA 175 FIFTH AVE, NEW YORK, NY 10010 USA 3169 SN 1434-6028 3170 J9 EUR PHYS J B 3171 JI Eur. Phys. J. B 3172 PD FEB 3173 PY 2001 3174 VL 19 3175 IS 4 3176 BP 583 3177 EP 587 3178 PG 5 3179 SC Physics, Condensed Matter 3180 GA 421MY 3181 UT ISI:000168069200011 3182 ER 3183 3184 PT J 3185 AU Pastor-Satorras, R 3186 Vespignani, A 3187 TI Epidemic spreading in scale-free networks 3188 SO PHYSICAL REVIEW LETTERS 3189 LA English 3190 DT Article 3191 ID SMALL-WORLD NETWORKS; INTERNET 3192 AB The Internet has a very complex connectivity recently modeled by the 3193 class of scale-free networks. This feature, which appears to be very 3194 efficient for a communications network, favors at the same time the 3195 spreading of computer viruses. We analyze real data from computer virus 3196 infections and find the average lifetime and persistence of viral 3197 strains on the Internet. We define a dynamical model for the spreading 3198 of infections on scale-free networks. finding the absence of an 3199 epidemic threshold and its associated critical behavior. This new 3200 epidemiological framework rationalizes data of computer viruses and 3201 could help in the understanding of other spreading phenomena on 3202 communication and social networks. 3203 C1 Univ Politecn Catalunya, Dept Fis & Engn Nucl, ES-08034 Barcelona, Spain. 3204 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 3205 RP Pastor-Satorras, R, Univ Politecn Catalunya, Dept Fis & Engn Nucl, 3206 Campus Nord,Modul B4, ES-08034 Barcelona, Spain. 3207 CR ALBERT R, 1999, NATURE, V401, P130 3208 AMARAL LAN, 2000, P NATL ACAD SCI USA, V97, P11149 3209 BAILEY NTJ, 1975, MATH THEORY INFECT D 3210 BARABASI AL, 1999, PHYSICA A, V272, P173 3211 BARABASI AL, 1999, SCIENCE, V286, P509 3212 BARRAT A, 2000, EUR PHYS J B, V13, P57 3213 CALDARELLI G, 2000, EUROPHYS LETT, V52, P386 3214 COHEN FB, 1994, SHORT COURSE COMPUTE 3215 ERDOS P, 1960, PUBL MATH I HUNG, V5, P17 3216 FALOUTSOS M, 1999, COMP COMM R, V29, P251 3217 HILL MK, 1997, UNDERSTANDING ENV PO 3218 KEPHART JO, 1991, P 1991 IEEE COMP SOC, P343 3219 KEPHART JO, 1993, IEEE SPECTRUM, V30, P20 3220 KEPHART JO, 1997, SCI AM, V277, P56 3221 MARRO J, 1999, NONEQUILIBRIUM PHASE 3222 MEDINA A, 2000, COMPUT COMMUN REV, V30, P18 3223 MOORE C, 2000, PHYS REV E B, V61, P5678 3224 MURRAY JD, 1993, MATH BIOL 3225 MURRAY WH, 1988, COMPUT SECUR, V7, P130 3226 PASTORSATORRAS R, UNPUB 3227 SZABO G, 2000, PHYS REV E B, V62, P7474 3228 WASSERMAN S, 1994, SOCIAL NETWORK ANAL 3229 WATTS DJ, 1998, NATURE, V393, P440 3230 WHITE SR, 1998, P VIR B C MUN 1998 3231 NR 24 3232 TC 451 3233 PU AMERICAN PHYSICAL SOC 3234 PI COLLEGE PK 3235 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 3236 SN 0031-9007 3237 J9 PHYS REV LETT 3238 JI Phys. Rev. Lett. 3239 PD APR 2 3240 PY 2001 3241 VL 86 3242 IS 14 3243 BP 3200 3244 EP 3203 3245 PG 4 3246 SC Physics, Multidisciplinary 3247 GA 417ZX 3248 UT ISI:000167866300072 3249 ER 3250 3251 PT J 3252 AU Miguel, MC 3253 Vespignani, A 3254 Zapperi, S 3255 Weiss, J 3256 Grasso, JR 3257 TI Intermittent dislocation flow in viscoplastic deformation 3258 SO NATURE 3259 LA English 3260 DT Article 3261 ID ACOUSTIC-EMISSION; SINGLE-CRYSTALS; DYNAMICS; SIMULATION; PATTERNS; 3262 LINES; ICE 3263 AB The viscoplastic deformation (creep) of crystalline materials under 3264 constant stress involves the motion of a large number of interacting 3265 dislocations(1). Analytical methods and sophisticated 'dislocation 3266 dynamics' simulations have proved very effective in the study of 3267 dislocation patterning, and have led to macroscopic constitutive laws 3268 of plastic deformation(2-9). Yet, a statistical analysis of the 3269 dynamics of an assembly of interacting dislocations has not hitherto 3270 been performed. Here we report acoustic emission measurements on 3271 stressed ice single crystals, the results of which indicate that 3272 dislocations move in a scale-free intermittent fashion. This result is 3273 confirmed by numerical simulations of a model of interacting 3274 dislocations that successfully reproduces the main features of the 3275 experiment. We rnd that dislocations generate a slowly evolving 3276 configuration landscape which coexists with rapid collective 3277 rearrangements. These rearrangements involve a comparatively small 3278 fraction of the dislocations and lead to an intermittent behaviour of 3279 the net plastic response. This basic dynamical picture appears to be a 3280 generic feature in the deformation of many other materials(10-12). 3281 Moreover, it should provide a framework for discussing fundamental 3282 aspects of plasticity that goes beyond standard mean-field approaches 3283 that see plastic deformation as a smooth laminar flow. 3284 C1 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 3285 Univ Barcelona, Fac Fis, Dept Fis Fonamental, E-08028 Barcelona, Spain. 3286 Univ La Sapienza, INFM, I-00185 Rome, Italy. 3287 CNRS, LGGE, F-38402 St Martin Dheres, France. 3288 LGIT, F-38041 Grenoble 9, France. 3289 RP Miguel, MC, Abdus Salam Int Ctr Theoret Phys, POB 586, I-34100 Trieste, 3290 Italy. 3291 CR AMODEO RJ, 1990, PHYS REV B B, V41, P6958 3292 ANANTHAKRISHNA G, 1999, PHYS REV E A, V60, P5455 3293 BECKER R, 1932, Z PHYS, V79, P566 3294 BENGUS VZ, 1966, PHYS STATUS SOLIDI, V14, P215 3295 DUVAL P, 1983, J PHYS CHEM-US, V87, P4066 3296 FOURNET R, 1996, PHYS REV B, V53, P6283 3297 GROMA I, 1993, PHILOS MAG A, V67, P1459 3298 HAHNER P, 1996, APPL PHYS A-MATER, V62, P473 3299 HAHNER P, 1998, PHYS REV LETT, V81, P2470 3300 HIRTH JP, 1992, THEORY DISLOCATIONS 3301 JENSEN HJ, 1998, SELF ORG CRITICALITY 3302 KARDAR M, 1998, PHYS REP, V301, P85 3303 LEPINOUX J, 1987, SCRIPTA METALL, V21, P833 3304 NEUHAUSER H, 1983, DISLOCATIONS SOLIDS, V6, P319 3305 PETRENKO VF, 1994, 9412 US ARM COLD REG 3306 ROUBY D, 1983, PHILOS MAG A, V47, P671 3307 SEVILLANO JG, 1991, SCRIPTA METALL MATER, V25, P355 3308 THOMSON R, 1998, PHYS REV LETT, V81, P3884 3309 WEISS J, 1997, J PHYS CHEM B, V101, P6113 3310 WEISS J, 2000, J GEOPHYS RES-SOL EA, V105, P433 3311 ZAISER M, 1999, ACTA MATER, V47, P2463 3312 NR 21 3313 TC 78 3314 PU MACMILLAN PUBLISHERS LTD 3315 PI LONDON 3316 PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND 3317 SN 0028-0836 3318 J9 NATURE 3319 JI Nature 3320 PD APR 5 3321 PY 2001 3322 VL 410 3323 IS 6829 3324 BP 667 3325 EP 671 3326 PG 6 3327 SC Multidisciplinary Sciences 3328 GA 418DJ 3329 UT ISI:000167875400040 3330 ER 3331 3332 PT J 3333 AU Pietronero, L 3334 Tosatti, E 3335 Tosatti, V 3336 Vespignani, A 3337 TI Explaining the uneven distribution of numbers in nature: the laws of 3338 Benford and Zipf 3339 SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS 3340 LA English 3341 DT Article 3342 AB The distribution of first digits in numbers series obtained from very 3343 different origins shows a marked asymmetry in favor of small digits 3344 that goes under the name of Benford's law. We analyze in detail this 3345 property for different data sets and give a general explanation for the 3346 origin of the Benford's law in terms of multiplicative processes. We 3347 show that this law can be also generalized to series of numbers 3348 generated from more complex systems like the catalogs of seismic 3349 activity. Finally, we derive a relation between the generalized 3350 Benford's law and the popular Zipf's law which characterize the rank 3351 order statistics and has been extensively applied to many problems 3352 ranging from city population to linguistics. (C) 2001 Published by 3353 Elsevier Science B.V. 3354 C1 Univ Rome La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. 3355 Univ Rome La Sapienza, Unita INFM, I-00185 Rome, Italy. 3356 SISSA, ISAS, I-34014 Trieste, Italy. 3357 SISSA, Unita INFM Trieste, I-34014 Trieste, Italy. 3358 Abdus Salam Int Ctr Theoret Phys, ICTP, I-34100 Trieste, Italy. 3359 RP Pietronero, L, Univ Rome La Sapienza, Dipartimento Fis, P A Moro 2, 3360 I-00185 Rome, Italy. 3361 CR BAK P, 1996, NATURE WORKS SCI SEL 3362 BENFORD F, 1938, P AM PHILOS SOC, V78, P551 3363 GELLMANN M, 1994, QUARK JAGUAR ADVENTU 3364 GUTENBERG B, 1944, B SEISMOL SOC AM, V34, P185 3365 HILL TP, 1998, AM SCI, V86, P358 3366 LEY E, 1996, AM STAT, V50, P311 3367 MANDELBROT BB, 1982, FRACTAL GEOMETRY NAT 3368 NEWCOMB S, 1881, AM J MATH, V4, P39 3369 NIGRINI M, 1996, J AM TAXATION ASS, V18, P72 3370 RAIMI R, 1969, SCI AM DEC, P109 3371 RAIMI RA, 1976, AM MATH MONTHLY, V83, P521 3372 RICHARDS SP, 1982, NUMBER YOUR THOUGHTS 3373 SCHATTE P, 1988, J INF PROCESS CYBERN, V24, P443 3374 VICSEK T, 1992, FRACTAL GROWTH PHENO 3375 ZIPF GK, 1949, HUMAN BEHAV PRINCIPL 3376 NR 15 3377 TC 18 3378 PU ELSEVIER SCIENCE BV 3379 PI AMSTERDAM 3380 PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS 3381 SN 0378-4371 3382 J9 PHYSICA A 3383 JI Physica A 3384 PD APR 1 3385 PY 2001 3386 VL 293 3387 IS 1-2 3388 BP 297 3389 EP 304 3390 PG 8 3391 SC Physics, Multidisciplinary 3392 GA 413TP 3393 UT ISI:000167628300023 3394 ER 3395 3396 PT J 3397 AU Pastor-Satorras, R 3398 Vespignani, A 3399 TI Anomalous scaling in the Zhang model 3400 SO EUROPEAN PHYSICAL JOURNAL B 3401 LA English 3402 DT Article 3403 ID SELF-ORGANIZED CRITICALITY; ABELIAN SANDPILE; UNIVERSALITY; EVENTS 3404 AB We apply the moment analysis technique to analyze large scale 3405 simulations of the Zhang sandpile model. We find that this model shows 3406 different scaling behavior depending on the update mechanism used. With 3407 the standard parallel updating, the Zhang model violates the 3408 finite-size scaling hypothesis, and it also appears to be incompatible 3409 with the more general multifractal scaling form. This makes impossible 3410 its affiliation to any one of the known universality classes of 3411 sandpile models. With sequential updating, it shows scaling for the 3412 size and area distribution. The introduction of stochasticity into the 3413 toppling rules of the parallel Zhang model leads to a scaling behavior 3414 compatible with the Manna universality class. 3415 C1 Univ Barcelona, Fac Fis, Dept Fis Fonamental, E-08028 Barcelona, Spain. 3416 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 3417 RP Pastor-Satorras, R, Univ Barcelona, Fac Fis, Dept Fis Fonamental, Av 3418 Diagonal 647, E-08028 Barcelona, Spain. 3419 CR BAK P, 1987, PHYS REV LETT, V59, P381 3420 CARDY JL, 1988, CURRENT PHYSICS SOUR, V2 3421 CHESSA A, 1999, COMPUT PHYS COMMUN, V121, P299 3422 DEMENECH M, 1998, PHYS REV E A, V58, R2677 3423 DHAR D, 1999, PHYSICA A, V263, P4 3424 GIACOMETTI A, 1998, PHYS REV E, V58, P247 3425 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 3426 JENSEN HJ, 1998, SELF ORG CRITICALITY 3427 KADANOFF LP, 1989, PHYS REV A, V39, P6524 3428 LUBECK S, CONDMAT0008304 3429 LUBECK S, 1997, PHYS REV E, V56, P1590 3430 LUBECK S, 2000, PHYS REV E, V61, P204 3431 MANNA SS, 1991, J PHYS A, V24, L363 3432 MILSHTEIN E, 1998, PHYS REV E, V58, P303 3433 TEBALDI C, 1999, PHYS REV LETT, V83, P3952 3434 VAZQUEZ A, CONDMAT0003420 3435 VESPIGNANI A, 1998, PHYS REV E, V57, P6345 3436 VESPIGNANI A, 2000, PHYS REV E A, V62, P4564 3437 ZHANG YC, 1989, PHYS REV LETT, V63, P470 3438 NR 19 3439 TC 8 3440 PU SPRINGER-VERLAG 3441 PI NEW YORK 3442 PA 175 FIFTH AVE, NEW YORK, NY 10010 USA 3443 SN 1434-6028 3444 J9 EUR PHYS J B 3445 JI Eur. Phys. J. B 3446 PD NOV 3447 PY 2000 3448 VL 18 3449 IS 2 3450 BP 197 3451 EP 200 3452 PG 4 3453 SC Physics, Condensed Matter 3454 GA 381QH 3455 UT ISI:000165774100003 3456 ER 3457 3458 PT J 3459 AU Pastor-Satorras, R 3460 Vespignani, A 3461 TI Field theory of absorbing phase transitions with a nondiffusive 3462 conserved field 3463 SO PHYSICAL REVIEW E 3464 LA English 3465 DT Article 3466 ID SELF-ORGANIZED CRITICALITY; ABELIAN SANDPILE; CRITICAL-BEHAVIOR; MODEL; 3467 RENORMALIZATION; SYSTEMS; EVENTS; STATES 3468 AB We investigate the critical behavior of a reaction-diffusion system 3469 exhibiting a continuous absorbing-state phase transition. The 3470 reaction-diffusion system strictly conserves the total density of 3471 particles, represented as a nondiffusive conserved field, and allows an 3472 infinite number of absorbing configurations. Numerical results show 3473 that it belongs to a wide universality class that also includes 3474 stochastic sandpile models. We derive microscopically the field theory 3475 representing this universality class. 3476 C1 Univ Barcelona, Fac Fis, Dept Fis Fonamental, E-08028 Barcelona, Spain. 3477 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 3478 RP Pastor-Satorras, R, Univ Barcelona, Fac Fis, Dept Fis Fonamental, Ave 3479 Diagonal 647, E-08028 Barcelona, Spain. 3480 CR ALBANO EV, 1992, J PHYS A, V25, P2557 3481 BAK P, 1987, PHYS REV LETT, V59, P381 3482 CARDY J, 1996, PHYS REV LETT, V77, P4780 3483 CARDY JL, 1980, J PHYS A, V13, L423 3484 CHESSA A, 1999, COMPUT PHYS COMMUN, V121, P299 3485 DEMENECH M, 1998, PHYS REV E A, V58, R2677 3486 DHAR D, 1999, PHYSICA A, V263, P4 3487 DICKMAN R, 1998, PHYS REV E A, V57, P5095 3488 GRASSBERGER P, 1979, ANN PHYS-NEW YORK, V122, P373 3489 GRASSBERGER P, 1995, PHYS LETT A, V200, P277 3490 JANSSEN HK, 1981, Z PHYS B CON MAT, V42, P151 3491 JANSSEN HK, 1999, EUR PHYS J B, V7, P137 3492 JENSEN HJ, 1998, SELF ORGANIZED CRITI 3493 JENSEN I, 1993, PHYS REV E, V48, P1710 3494 JENSEN I, 1993, PHYS REV LETT, V70, P1465 3495 KREE R, 1989, PHYS REV A, V39, P2214 3496 LEE BP, 1995, J STAT PHYS, V80, P971 3497 LUBECK S, 2000, PHYS REV E, V61, P204 3498 MANNA SS, 1991, J PHYS A, V24, L363 3499 MARRO J, 1999, NONEQUILIBRIUM PHASE 3500 MENDES JFF, 1994, J PHYS A-MATH GEN, V27, P3019 3501 MILSHTEIN E, 1998, PHYS REV E, V58, P303 3502 MUNOZ MA, COMMUNICATION 3503 NAKANISHI K, 1997, PHYS REV E, V55, P4012 3504 PACZUSKI M, 1994, EUROPHYS LETT, V27, P97 3505 PACZUSKI M, 1994, EUROPHYS LETT, V28, P295 3506 ROSSI M, 2000, PHYS REV LETT, V85, P1803 3507 TEBALDI C, 1999, PHYS REV LETT, V83, P3952 3508 VANWIJLAND F, 1998, PHYSICA A, V251, P179 3509 VESPIGNANI A, CONDMAT0003285 3510 VESPIGNANI A, 1998, PHYS REV LETT, V81, P5676 3511 NR 31 3512 TC 10 3513 PU AMERICAN PHYSICAL SOC 3514 PI COLLEGE PK 3515 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 3516 SN 1063-651X 3517 J9 PHYS REV E 3518 JI Phys. Rev. E 3519 PD NOV 3520 PY 2000 3521 VL 62 3522 IS 5 3523 PN Part A 3524 BP R5875 3525 EP R5878 3526 PG 4 3527 SC Physics, Fluids & Plasmas; Physics, Mathematical 3528 GA 374JH 3529 UT ISI:000165341700001 3530 ER 3531 3532 PT J 3533 AU Pastor-Satorras, R 3534 Vespignani, A 3535 TI Critical behavior and conservation in directed sandpiles 3536 SO PHYSICAL REVIEW E 3537 LA English 3538 DT Article 3539 ID SELF-ORGANIZED CRITICALITY; UPPER CRITICAL DIMENSION; ABELIAN SANDPILE; 3540 MODELS; UNIVERSALITY; EVENTS 3541 AB We perform large-scale simulations of directed sandpile models with 3542 both deterministic and stochastic toppling rules. Our results show the 3543 existence of two distinct universality classes. We also provide 3544 numerical simulations of directed models in the presence of bulk 3545 dissipation. The numerical results indicate that the way in which 3546 dissipation is implemented is irrelevant for the determination of the 3547 critical behavior. The analysis of the self-affine properties of 3548 avalanches shows the existence of a subset of superuniversal exponents, 3549 whose value is independent of the universality class. This feature is 3550 accounted for by means of a phenomenological description of the energy 3551 balance condition in these models. 3552 C1 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 3553 RP Pastor-Satorras, R, Abdus Salam Int Ctr Theoret Phys, POB 586, I-34100 3554 Trieste, Italy. 3555 CR ALAVA M, CONDMAT0002406 3556 BAK P, 1987, PHYS REV LETT, V59, P381 3557 BAK P, 1988, PHYS REV A, V38, P364 3558 CARDY JL, 1988, CURRENT PHYSICS SOUR, V2 3559 CHESSA A, 1998, PHYS REV E, V57, R6241 3560 CHESSA A, 1999, COMPUT PHYS COMMUN, V121, P299 3561 CHRISTENSEN K, 1993, PHYS REV E, V48, P3361 3562 DEMENECH M, 1998, PHYS REV E A, V58, R2677 3563 DHAR D, 1989, PHYS REV LETT, V63, P1659 3564 DHAR D, 1999, PHYSICA A, V263, P4 3565 DICKMAN R, 1998, PHYS REV E A, V57, P5095 3566 DROSSEL B, 2000, PHYS REV E, V61, R2168 3567 GRADSHTEYN IS, 1979, TABLE INTEGRALS SERI 3568 GRASSBERGER P, 1995, PHYS LETT A, V200, P277 3569 HASTY J, 1998, PHYS REV LETT, V81, P1722 3570 JENSEN HJ, 1998, SEFL ORG CRITICALITY 3571 KADANOFF LP, 1989, PHYS REV A, V39, P6524 3572 KINZEL W, 1983, PERCOLATION STRUCTUR, V5, CH18 3573 KLOSTER MN, CONDMAT0005528 3574 LAURITSEN KB, CONDMAT9903346 3575 LUBECK S, 1998, PHYS REV E A, V58, P2957 3576 LUBECK S, 2000, PHYS REV E, V61, P204 3577 MANNA SS, 1990, J STAT PHYS, V61, P923 3578 MANNA SS, 1990, PHYS REV E, V60, R5005 3579 MANNA SS, 1991, J PHYS A, V24, L363 3580 MARRO J, 1999, NONEQUILIBRIUM PHASE 3581 MILSHTEIN E, 1998, PHYS REV E, V58, P303 3582 PACZUSKI M, CONDMAT0005340 3583 PACZUSKI M, 1994, EUROPHYS LETT, V27, P97 3584 PACZUSKI M, 1994, EUROPHYS LETT, V28, P295 3585 PACZUSKI M, 1996, PHYS REV LETT, V77, P111 3586 PASTORSATORRAS R, 2000, J PHYS A-MATH GEN, V33, L33 3587 TADIC B, 1997, PHYS REV LETT, V79, P1519 3588 TANG C, 1988, PHYS REV LETT, V60, P2347 3589 TEBALDI C, 1999, PHYS REV LETT, V83, P3952 3590 TSUCHIYA T, 1999, J PHYS A-MATH GEN, V32, P1629 3591 VAZQUEZ A, CONDMAT0003420 3592 VESPIGNANI A, 1998, PHYS REV E, V57, P6345 3593 VESPIGNANI A, 1998, PHYS REV LETT, V81, P5676 3594 VESPIGNANI A, 2000, PHYS REV E A, V62, P4564 3595 NR 40 3596 TC 11 3597 PU AMERICAN PHYSICAL SOC 3598 PI COLLEGE PK 3599 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 3600 SN 1063-651X 3601 J9 PHYS REV E 3602 JI Phys. Rev. E 3603 PD NOV 3604 PY 2000 3605 VL 62 3606 IS 5 3607 PN Part A 3608 BP 6195 3609 EP 6205 3610 PG 11 3611 SC Physics, Fluids & Plasmas; Physics, Mathematical 3612 GA 374JH 3613 UT ISI:000165341700047 3614 ER 3615 3616 PT J 3617 AU Castellano, C 3618 Marsili, M 3619 Vespignani, A 3620 TI Nonequilibrium phase transition in a model for social influence 3621 SO PHYSICAL REVIEW LETTERS 3622 LA English 3623 DT Article 3624 AB We present extensive numerical simulations of the Axelrod's model for 3625 social influence, aimed at understanding the formation of cultural 3626 domains. This is a nonequilibrium model with short range interactions 3627 and a remarkably rich dynamical behavior. We study the phase diagram of 3628 the model and uncover a nonequilibrium phase transition separating an 3629 ordered (culturally polarized) phase from a disordered (culturally 3630 fragmented) one. The nature of the phase transition can be continuous 3631 or discontinuous depending on the model parameters. At the transition, 3632 the size of cultural regions is power-law distributed. 3633 C1 Univ Essen Gesamthsch, Fachbereich Phys, D-45117 Essen, Germany. 3634 INFM, Trieste SISSA Unit, I-34014 Trieste, Italy. 3635 Abdus Salam Int Ctr Theoret Phys, I-34014 Trieste, Italy. 3636 RP Castellano, C, Univ Essen Gesamthsch, Fachbereich Phys, D-45117 Essen, 3637 Germany. 3638 CR ANDERSON PW, 1998, EC EVOLVING COMPLEX 3639 AXELROD R, 1997, COMPLEXITY COOPERATI 3640 AXELROD R, 1997, J CONFLICT RESOLUT, V41, P203 3641 AXTELL R, 1996, COMPUTATIONAL MATH O, V1, P123 3642 BIALAS P, 1997, NUCL PHYS B, V493, P505 3643 BRAY AJ, 1994, ADV PHYS, V43, P357 3644 FRACHEBOURG L, 1996, PHYS REV E, V53, P3009 3645 LIGGETT TM, 1985, INTERACTING PARTICLE 3646 MARSILI M, 1998, PHYS REV LETT, V80, P2741 3647 SCHEUCHER M, 1988, J STAT PHYS, V53, P279 3648 STAUFFER D, 1985, INTRO PERCOLATION TH 3649 NR 11 3650 TC 56 3651 PU AMERICAN PHYSICAL SOC 3652 PI COLLEGE PK 3653 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 3654 SN 0031-9007 3655 J9 PHYS REV LETT 3656 JI Phys. Rev. Lett. 3657 PD OCT 16 3658 PY 2000 3659 VL 85 3660 IS 16 3661 BP 3536 3662 EP 3539 3663 PG 4 3664 SC Physics, Multidisciplinary 3665 GA 363YU 3666 UT ISI:000089865900051 3667 ER 3668 3669 PT J 3670 AU Vespignani, A 3671 Dickman, R 3672 Munoz, MA 3673 Zapperi, S 3674 TI Absorbing-state phase transitions in fixed-energy sandpiles 3675 SO PHYSICAL REVIEW E 3676 LA English 3677 DT Review 3678 ID SELF-ORGANIZED CRITICALITY; CHARGE-DENSITY WAVES; ANNIHILATING 3679 RANDOM-WALKS; TANG-WIESENFELD SANDPILE; ABELIAN SANDPILE; 3680 RENORMALIZATION-GROUP; DIRECTED PERCOLATION; CRITICAL EXPONENTS; 3681 QUENCHED DISORDER; CRITICAL-BEHAVIOR 3682 AB We study sandpile models as closed systems, with the conserved energy 3683 density zeta playing the role of an external parameter. The critical 3684 energy density zeta (c) marks a nonequilibrium phase transition between 3685 active and absorbing states. Several fixed-energy sandpiles are studied 3686 in extensive simulations of stationary and transient properties, as 3687 well as the dynamics of roughening in an interface-height 3688 representation. Our primary goal is to identify the universality 3689 classes of such models, in hopes of assessing the validity of two 3690 recently proposed approaches to sandpiles: a phenomenological continuum 3691 Langevin description with absorbing states, and a mapping to driven 3692 interface dynamics in random media. 3693 C1 Abdus Salam Int Ctr Theoret Phys, ICTP, I-34100 Trieste, Italy. 3694 Univ Fed Minas Gerais, ICEx, Dept Fis, BR-30161970 Belo Horizonte, MG, Brazil. 3695 Univ Granada, Inst Carlos Theoret & Computat Phys 1, E-18071 Granada, Spain. 3696 Univ Granada, Dept Electromagnet & Fis Mat, E-18071 Granada, Spain. 3697 Univ Roma La Sapienza, Dipartimento Fis, Sez Roma 1, INFM, I-00185 Rome, Italy. 3698 RP Vespignani, A, Abdus Salam Int Ctr Theoret Phys, ICTP, POB 586, I-34100 3699 Trieste, Italy. 3700 CR ALAVA M, CONDMAT0002406 3701 ALON U, 1996, PHYS REV LETT, V76, P2746 3702 BAK P, 1987, PHYS REV LETT, V59, P381 3703 BAK P, 1988, PHYS REV A, V38, P364 3704 BAKSNEPPEN SOC, 1994, EUROPHYS LETT, V27, P97 3705 BARBASI AL, 1995, FRACTAL CONCEPTS SUR 3706 BARRAT A, 1999, PHYS REV LETT, V83, P1962 3707 BENHUR A, 1996, PHYS REV E, V53, P1317 3708 BISWAS P, 1998, PHYS REV E A, V58, P1266 3709 BRAY AJ, 1994, ADV PHYS, V43, P357 3710 CALFIERO R, 1998, PHYS REV E, V57, P5060 3711 CARDY J, 1996, PHYS REV LETT, V77, P4780 3712 CARDY JL, 1980, J PHYS A, V13, L423 3713 CHESSA A, 1998, PHYS REV LETT, V80, P4217 3714 CHESSA A, 1999, COMPUT PHYS COMMUN, V121, P299 3715 CHESSA A, 1999, PHYS REV E A, V59, R12 3716 DEMENECH M, 1998, PHYS REV E A, V58, R2677 3717 DHAR D, CONDMAT9909009 3718 DHAR D, 1989, PHYS REV LETT, V63, P1659 3719 DHAR D, 1990, PHYS REV LETT, V64, P1613 3720 DHAR D, 1999, PHYSICA A, V270, P69 3721 DIAZGUILERA A, 1994, EUROPHYS LETT, V26, P177 3722 DICKMAN R, CONDMAT9909347 3723 DICKMAN R, UNPUB 3724 DICKMAN R, 1996, NONEQUILIBRIUM STAT 3725 DICKMAN R, 1998, PHYS REV E A, V57, P1263 3726 DICKMAN R, 1998, PHYS REV E A, V57, P5095 3727 DOI M, 1976, J PHYS A, V9, P1465 3728 FAMILY F, 1985, J PHYS A, V18, L75 3729 FISHER ME, 1971, P INT SUMM SCH E FER 3730 FISHER ME, 1972, PHYS REV LETT, V28, P1516 3731 GRASSBERGER P, COMMUNICATION 3732 GRASSBERGER P, 1982, Z PHYS B CON MAT, V47, P365 3733 GRASSBERGER P, 1984, J PHYS A, V17, L105 3734 GRASSBERGER P, 1989, J PHYS A, V22, L1103 3735 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 3736 GRASSBERGER P, 1995, PHYS LETT A, V200, P277 3737 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 3738 GRINSTEIN G, 1997, LECT NOTES PHYS, V493, P223 3739 HASTY J, 1997, J STAT PHYS, V86, P1179 3740 HINRICHSEN H, 1997, PHYS REV E A, V55, P219 3741 HWA T, 1992, PHYS REV A, V45, P7002 3742 HWANG W, 1998, PHYS REV E, V57, P6438 3743 IVASHKEVICH EV, 1994, J PHYS A-MATH GEN, V27, P3643 3744 IVASHKEVICH EV, 1994, PHYSICA A, V209, P347 3745 JANSSEN HK, 1981, Z PHYS B CON MAT, V42, P151 3746 JANSSEN HK, 1989, Z PHYS B CON MAT, V73, P539 3747 JANSSEN HK, 1997, PHYS REV E B, V55, P6253 3748 JENSEN I, 1993, PHYS REV E, V48, P1710 3749 JENSEN I, 1993, PHYS REV LETT, V70, P1465 3750 JENSEN I, 1994, PHYS REV E, V50, P3623 3751 KERTESZ J, 1989, PHYS REV LETT, V62, P2571 3752 KINZEL W, 1985, Z PHYS B CON MAT, V58, P229 3753 KOBAYASHI H, 1997, J PHYS SOC JPN, V66, P2367 3754 KTITAREV DV, 2000, PHYS REV E, V61, P81 3755 LAURITSEN KB, CONDMAT9903346 3756 LEE BP, 1995, J STAT PHYS, V80, P971 3757 LESCHHORN H, 1997, ANN PHYS-LEIPZIG, V6, P1 3758 LIGGET TM, 1985, INTERACTING PARTICLE 3759 LOPEZ JM, 1997, J PHYS I, V7, P1191 3760 LOPEZ JM, 1997, PHYS REV E, V56, P3993 3761 LOPEZ JM, 1999, PHYS REV LETT, V83, P4594 3762 LUBECK S, 1997, PHYS REV E A, V56, P5138 3763 LUBECK S, 1997, PHYS REV E, V55, P4095 3764 LUBECK S, 2000, PHYS REV E, V61, P204 3765 MAJUMDAR SN, 1992, PHYSICA A, V185, P129 3766 MANNA SS, 1990, J STAT PHYS, V59, P509 3767 MANNA SS, 1991, J PHYS A, V24, L363 3768 MARRO J, 1999, NONEQUILIBRIUM PHASE 3769 MARSILI M, 1994, J STAT PHYS, V77, P733 3770 MASLOV S, 1996, PHYSICA A, V223, P1 3771 MEHTA A, 1996, PHYS REV E A, V53, P92 3772 MENDES JFF, 1994, J PHYS A-MATH GEN, V27, P3019 3773 MENYHARD N, 1996, J PHYS A-MATH GEN, V29, P7739 3774 MONTAKHAB A, 1998, PHYS REV E A, V58, P5608 3775 MOREIRA AG, 1996, PHYS REV E, V54, P3090 3776 MUNOZ MA, UNPUB 3777 MUNOZ MA, 1996, PHYS REV LETT, V76, P451 3778 MUNOZ MA, 1998, J STAT PHYS, V91, P541 3779 MUNOZ MA, 1999, PHYS REV E B, V59, P6175 3780 NARAYAN O, 1993, PHYS REV B, V48, P7030 3781 NARAYAN O, 1994, PHYS REV B, V49, P244 3782 NOEST AJ, 1986, PHYS REV LETT, V57, P90 3783 NOEST AJ, 1988, PHYS REV B, V38, P2715 3784 PACZUSKI M, 1996, PHYS REV LETT, V77, P111 3785 PANG NN, 1999, PHYS REV E A, V59, P234 3786 PARISI G, 1991, EUROPHYS LETT, V16, P321 3787 PARISI G, 1991, PHYSICA A, V179, P16 3788 PASTORSATORRAS R, COMMUNICATION 3789 PASTORSATORRAS R, 2000, J PHYS A-MATH GEN, V33, L33 3790 PELITI L, 1985, J PHYS-PARIS, V46, P1469 3791 PIETRONERO L, 1991, PHYSICA A, V173, P129 3792 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 3793 PRIEZZHEV VB, CONDMAT9904054 3794 PRIEZZHEV VB, 1994, J STAT PHYS, V74, P955 3795 SARMA D, 1996, PHYS REV E, V53, P359 3796 SORNETTE D, 1995, J PHYS I, V5, P325 3797 TADIC B, 1997, PHYS REV LETT, V79, P1519 3798 TAKAYASU H, 1992, PHYS REV LETT, V68, P3060 3799 TANG C, 1988, PHYS REV LETT, V60, P2347 3800 TEBALDI C, 1999, PHYS REV LETT, V83, P3952 3801 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 3802 VESPIGNANI A, 1998, PHYS REV E, V57, P6345 3803 VESPIGNANI A, 1998, PHYS REV LETT, V81, P5676 3804 ZAPPERI S, 1995, PHYS REV LETT, V75, P4071 3805 ZHANG SD, 1999, PHYS REV E, V60, P259 3806 ZHANG YC, 1989, PHYS REV LETT, V63, P470 3807 NR 107 3808 TC 66 3809 PU AMERICAN PHYSICAL SOC 3810 PI COLLEGE PK 3811 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 3812 SN 1063-651X 3813 J9 PHYS REV E 3814 JI Phys. Rev. E 3815 PD OCT 3816 PY 2000 3817 VL 62 3818 IS 4 3819 PN Part A 3820 BP 4564 3821 EP 4582 3822 PG 19 3823 SC Physics, Fluids & Plasmas; Physics, Mathematical 3824 GA 365XY 3825 UT ISI:000089976800018 3826 ER 3827 3828 PT J 3829 AU Rossi, M 3830 Pastor-Satorras, R 3831 Vespignani, A 3832 TI Universality class of absorbing phase transitions with a conserved field 3833 SO PHYSICAL REVIEW LETTERS 3834 LA English 3835 DT Article 3836 ID SELF-ORGANIZED CRITICALITY; CRITICAL-BEHAVIOR; ABELIAN SANDPILE; 1/F 3837 NOISE; MODEL; SYSTEMS; STATES; PERCOLATION; LATTICE; EVENTS 3838 AB We investigate the critical behavior of systems exhibiting a continuous 3839 absorbing phase transition in the presence of a conserved field coupled 3840 to the order parameter. The results obtained point out the existence of 3841 a new universality class of nonequilibrium phase transitions that 3842 characterizes a vast set of systems including conserved threshold 3843 transfer processes and stochastic sandpile models. 3844 C1 SISSA, Int Sch Adv Studies, I-34014 Trieste, Italy. 3845 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 3846 RP Rossi, M, SISSA, Int Sch Adv Studies, Via Beirut 2-4, I-34014 Trieste, 3847 Italy. 3848 CR ALBANO EV, 1992, J PHYS A, V25, P2557 3849 BAK P, 1987, PHYS REV LETT, V59, P381 3850 CARDY J, 1996, PHYS REV LETT, V77, P4780 3851 CARDY JL, 1980, J PHYS A, V13, L423 3852 CHESSA A, 1999, COMPUT PHYS COMMUN, V121, P299 3853 CHRISTENSEN K, 1996, PHYS REV LETT, V77, P107 3854 DEMENECH M, 1998, PHYS REV E A, V58, R2677 3855 DHAR D, 1999, PHYSICA A, V263, P4 3856 DICKMAN R, 1998, PHYS REV E A, V57, P5095 3857 DICKMAN R, 2000, BRAZ J PHYS, V30, P27 3858 GRASSBERGER P, 1979, ANN PHYS-NEW YORK, V122, P373 3859 GRASSBERGER P, 1982, Z PHYS B CON MAT, V47, P365 3860 GRASSBERGER P, 1983, MATH BIOSCI, V63, P157 3861 JANSSEN HK, 1981, Z PHYS B CON MAT, V42, P151 3862 JANSSEN HK, 1985, Z PHYS B CON MAT, V58, P311 3863 JENSEN HJ, 1990, PHYS REV LETT, V64, P3103 3864 JENSEN HJ, 1998, SELF ORGANIZED CRITI 3865 JENSEN I, 1993, PHYS REV E, V48, P1710 3866 JENSEN I, 1993, PHYS REV LETT, V70, P1465 3867 LUBECK S, 2000, PHYS REV E, V61, P204 3868 MANNA SS, 1991, J PHYS A, V24, L363 3869 MARRO J, 1999, NONEQUILIBRIUM PHASE 3870 MENDES JFF, 1994, J PHYS A-MATH GEN, V27, P3019 3871 MUNOZ MA, 1999, PHYS REV E B, V59, P6175 3872 TEBALDI C, 1999, PHYS REV LETT, V83, P3952 3873 VANWIJLAND F, 1998, PHYSICA A, V251, P179 3874 VESPIGNANI A, CONDMAT0003285 3875 VESPIGNANI A, 1998, PHYS REV LETT, V81, P5676 3876 NR 28 3877 TC 76 3878 PU AMERICAN PHYSICAL SOC 3879 PI COLLEGE PK 3880 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 3881 SN 0031-9007 3882 J9 PHYS REV LETT 3883 JI Phys. Rev. Lett. 3884 PD AUG 28 3885 PY 2000 3886 VL 85 3887 IS 9 3888 BP 1803 3889 EP 1806 3890 PG 4 3891 SC Physics, Multidisciplinary 3892 GA 348BW 3893 UT ISI:000088965300006 3894 ER 3895 3896 PT J 3897 AU Pastor-Satorras, R 3898 Vespignani, A 3899 TI Corrections to scaling in the forest-fire model 3900 SO PHYSICAL REVIEW E 3901 LA English 3902 DT Article 3903 ID SELF-ORGANIZED CRITICALITY; SANDPILE; EVENTS 3904 AB We present a systematic study of corrections to scaling in the 3905 self-organized critical forest-fire model. The analysis of the 3906 steady-state condition for the density of trees allows us to pinpoint 3907 the presence of these corrections, which take the form of subdominant 3908 exponents modifying the standard finite-size scaling form. Applying an 3909 extended version of the moment analysis technique, we find the scaling 3910 region of the model and compute nontrivial corrections to scaling. 3911 C1 Int Ctr Theoret Phys, Condensed Matter Sect, I-34100 Trieste, Italy. 3912 RP Pastor-Satorras, R, Int Ctr Theoret Phys, Condensed Matter Sect, POB 3913 586, I-34100 Trieste, Italy. 3914 CR BAK P, 1987, PHYS REV LETT, V59, P381 3915 BAK P, 1990, PHYS LETT A, V147, P297 3916 CARDY J, 1996, SCALING RENORMALIZAT 3917 CARDY JL, 1988, FINITE SIZE SCALING, V2 3918 CHESSA A, 1999, COMPUT PHYS COMMUN, V121, P299 3919 CHESSA A, 1999, PHYS REV E A, V59, R12 3920 CHRISTENSEN K, 1993, PHYS REV LETT, V71, P2737 3921 CLAR S, 1996, J PHYS-CONDENS MAT, V8, P6803 3922 DEMENECH M, 1998, PHYS REV E A, V58, R2677 3923 DROSSEL B, 1992, PHYS REV LETT, V69, P1629 3924 DROSSEL B, 1994, PHYS REV E, V50, P1009 3925 GRASSBERGER P, 1993, J PHYS A-MATH GEN, V26, P2081 3926 JENSEN HJ, 1998, SELF ORGANIZED CRITI 3927 JOHANSEN A, 1994, PHYSICA D, V78, P186 3928 LUBECK S, 2000, PHYS REV E, V61, P204 3929 PASTORSATORRAS R, 2000, J PHYS A-MATH GEN, V33, L33 3930 PRESS WH, 1992, NUMERICAL RECIPES C 3931 SCHENK K, CONDMAT9904356 3932 TEBALDI C, 1999, PHYS REV LETT, V83, P3952 3933 NR 19 3934 TC 11 3935 PU AMERICAN PHYSICAL SOC 3936 PI COLLEGE PK 3937 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 3938 SN 1063-651X 3939 J9 PHYS REV E 3940 JI Phys. Rev. E 3941 PD MAY 3942 PY 2000 3943 VL 61 3944 IS 5 3945 PN Part A 3946 BP 4854 3947 EP 4859 3948 PG 6 3949 SC Physics, Fluids & Plasmas; Physics, Mathematical 3950 GA 314RH 3951 UT ISI:000087071000028 3952 ER 3953 3954 PT J 3955 AU Dickman, R 3956 Munoz, MA 3957 Vespignani, A 3958 Zapperi, S 3959 TI Paths to self-organized criticality 3960 SO BRAZILIAN JOURNAL OF PHYSICS 3961 LA English 3962 DT Review 3963 ID SUPERCONDUCTING VORTEX AVALANCHES; KINETIC CRITICAL PHENOMENON; 3964 ANNIHILATING RANDOM-WALKS; UPPER CRITICAL DIMENSION; ABELIAN SANDPILE 3965 MODEL; CHARGE-DENSITY WAVES; FOREST-FIRE MODEL; ABSORBING STATES; 3966 ACOUSTIC-EMISSION; CRITICAL-BEHAVIOR 3967 AB We present a pedagogical introduction to self-organized criticality 3968 (SOC), unraveling its connections with nonequilibrium phase 3969 transitions. There are several paths from a conventional critical point 3970 to SOC. They begin with an absorbing-state phase transition (directed 3971 percolation is a familiar example), and impose supervision or driving 3972 on the system; two commonly used methods are extremal dynamics, and 3973 driving at a rate approaching zero. We illustrate this in sandpiles, 3974 where SOC is a consequence of slow driving in a system exhibiting an 3975 absorbing-state phase transition with a conserved density. Other paths 3976 to SOC, in driven interfaces, the Bak-Sneppen model, and self-organized 3977 directed percolation, are also examined. We review the status of 3978 experimental realizations of SOC in Light of these observations. 3979 C1 Univ Fed Minas Gerais, ICEx, Dept Fis, BR-30161970 Belo Horizonte, MG, Brazil. 3980 Inst Carlos I Theoret & Computat Phys, Granada 18071, Spain. 3981 Dept Electromagnetismo & Fis Mat, Granada 18071, Spain. 3982 Int Ctr Theoret Phys, Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 3983 Ecole Phys & Chim Ind, PMMH, F-75231 Paris 05, France. 3984 RP Dickman, R, Univ Fed Minas Gerais, ICEx, Dept Fis, Caixa Postal 702, 3985 BR-30161970 Belo Horizonte, MG, Brazil. 3986 CR ALI AA, 1995, PHYS REV E A, V51, R2705 3987 ALI AA, 1995, PHYS REV E, V52, P4804 3988 BAGNOLI F, 1997, PHYS REV E, V55, P3970 3989 BAK P, 1987, PHYS REV LETT, V59, P381 3990 BAK P, 1988, PHYS REV A, V38, P364 3991 BAK P, 1993, PHYS REV LETT, V71, P4083 3992 BAK P, 1996, NATURE WORKS 3993 BARABASI AL, 1995, FRACTAL CONCEPTS SUR 3994 BARKHAUSEN H, 1919, PHYS Z, V20, P401 3995 BASSLER KE, 1998, PHYS REV LETT, V81, P3761 3996 BEAN CP, 1964, REV MOD PHYS, V36, P31 3997 BENHUR A, 1996, PHYS REV E, V53, P1317 3998 BERTOTTI G, 1994, J APPL PHYS, V75, P5490 3999 BEZUIDENHOUT C, 1990, ANN PROBAB, V18, P1462 4000 BRETZ M, 1992, PHYS REV LETT, V69, P2431 4001 BROEKER HM, CONDMAT9902195 4002 CANNELLI G, 1993, PHYS REV LETT, V70, P3923 4003 CARDY J, 1996, PHYS REV LETT, V77, P4780 4004 CARDY J, 1996, SCALING RENORMALIZAT, CH10 4005 CARDY JL, 1985, J PHYS A, V18, L267 4006 CARLSON JM, 1994, REV MOD PHYS, V66, P657 4007 CARRILLO L, 1998, PHYS REV LETT, V81, P1889 4008 CHEN K, 1991, PHYS REV A, V43, P625 4009 CHESSA A, 1998, PHYS REV E, V57, R6241 4010 CHESSA A, 1998, PHYS REV LETT, V80, P4217 4011 CHESSA A, 1999, PHYS REV E A, V59, R12 4012 CILIBERTO S, 1994, J PHYS I, V4, P223 4013 CLAR S, 1994, PHYS REV E A, V50, P1009 4014 CLAR S, 1996, J PHYS-CONDENS MAT, V8, P6803 4015 DEGENNES PG, 1966, SUPERCONDUCTIVITY ME 4016 DEMENECH M, 1998, PHYS REV E A, V58, R2677 4017 DHAR D, CONDMAT9909009 4018 DHAR D, 1989, PHYS REV LETT, V63, P1659 4019 DIAZGUILERA A, 1994, EUROPHYS LETT, V26, P177 4020 DICKMAN R, UNPUB 4021 DICKMAN R, 1996, NONEQUILIBRIUM STAT 4022 DICKMAN R, 1998, PHYS REV E A, V57, P5095 4023 DROSSEL B, 1992, PHYS REV LETT, V69, P1629 4024 DURIN G, 1995, FRACTALS, V3, P351 4025 ERZAN A, 1995, REV MOD PHYS, V67, P545 4026 FIELD S, 1995, PHYS REV LETT, V74, P1206 4027 FLYVBJERG H, 1993, PHYS REV LETT, V71, P4087 4028 FRETTE V, 1996, NATURE, V379, P49 4029 GABRIELLE A, CONDMAT9910425 4030 GARCIMARTIN A, 1997, PHYS REV LETT, V79, P3202 4031 GOPAL AD, 1995, PHYS REV LETT, V75, P2610 4032 GRASSBERGER P, 1982, Z PHYS B, V47, P465 4033 GRASSBERGER P, 1984, J PHYS A, V17, L105 4034 GRASSBERGER P, 1989, J PHYS A, V22, L1103 4035 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 4036 GRASSBERGER P, 1995, PHYS LETT A, V200, P277 4037 GRASSBERGER P, 1996, PHYSICA A, V224, P169 4038 GRINSTEIN G, 1991, J APPL PHYS 2B, V69, P5441 4039 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 4040 GRINSTEIN G, 1997, LECT NOTES PHYS, V493, P223 4041 GUARINO A, 1998, EUR PHYS J B, V6, P13 4042 HANSEN A, 1987, J PHYS A, V20, L873 4043 HARRIS TE, 1974, ANN PROBAB, V2, P969 4044 HASTY J, 1997, J STAT PHYS, V86, P1179 4045 HAVLIN S, 1993, GROWTH PATTERNS PHYS 4046 HINRICHSEN H, 1997, PHYS REV E A, V55, P219 4047 HWA T, 1992, PHYS REV A, V45, P7002 4048 HWANG W, 1998, PHYS REV E, V57, P6438 4049 JAEGER HM, 1989, PHYS REV LETT, V62, P40 4050 JAEGER HM, 1996, REV MOD PHYS, V68, P1259 4051 JANSSEN HK, 1981, Z PHYS, V42, P141 4052 JANSSEN HK, 1985, Z PHYS B CON MAT, V58, P311 4053 JENSEN I, 1993, PHYS REV E, V48, P1710 4054 JENSEN I, 1993, PHYS REV LETT, V70, P1465 4055 JENSEN I, 1994, PHYS REV E, V50, P3623 4056 JENSEN I, 1996, J PHYS A-MATH GEN, V29, P7013 4057 JOVANOVIC B, 1994, PHYS REV E, V50, P2403 4058 KADANOFF LP, 1989, PHYS REV A, V39, P6524 4059 KARDAR M, 1986, PHYS REV LETT, V56, P889 4060 KINZEL W, 1985, Z PHYS B CON MAT, V58, P229 4061 KIRCHNER JW, 1998, NATURE, V395, P337 4062 LAURITSEN KB, CONDMAT9903346 4063 LESCHHORN H, 1997, ANN PHYS-LEIPZIG, V6, P1 4064 LIGGETT TM, 1985, INTERACTING PARTICLE 4065 LIPOWSKI A, CONDMAT9910029 4066 LIPOWSKI A, 1999, PHYS REV E A, V60, P1516 4067 LUBECK S, 1997, PHYS REV E A, V56, P5138 4068 LUBECK S, 1997, PHYS REV E, V55, P4095 4069 LUBECK S, 1997, PHYS REV E, V56, P1590 4070 MACHTA J, 1993, PHYS REV E, V47, P4581 4071 MAES C, 1998, PHYS REV B, V57, P4987 4072 MALAMUD BD, 1998, SCIENCE, V281, P1840 4073 MANNA SS, 1990, J STAT PHYS, V59, P509 4074 MANNA SS, 1990, J STAT PHYS, V61, P923 4075 MANNA SS, 1991, J PHYS A, V24, L363 4076 MARRO J, 1999, NONEQUILIBRIUM PHASE 4077 MASLOV S, 1996, PHYSICA A, V223, P1 4078 MENYHARD N, 1996, J PHYS A-MATH GEN, V29, P7739 4079 MONTAKHAB A, 1998, PHYS REV E A, V58, P5608 4080 MUNOZ MA, 1999, PHYS REV E B, V59, P6175 4081 NARAYAN O, 1993, PHYS REV B, V48, P7030 4082 NARAYAN O, 1994, PHYS REV B, V49, P244 4083 OLSON CJ, 1997, PHYS REV B, V56, P6175 4084 PACZUSKI M, 1996, PHYS REV E A, V53, P414 4085 PACZUSKI M, 1996, PHYS REV LETT, V77, P111 4086 PARISI G, 1991, EUROPHYS LETT, V16, P321 4087 PERSSON BNJ, 1998, SLIDING FRICTION 4088 PETRI A, 1994, PHYS REV LETT, V73, P3423 4089 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 4090 ROUX S, 1994, J PHYS I, V4, P515 4091 RUNDLE JB, 1995, P SANT FE I WORKSH R 4092 RUNDLE JB, 1996, PHYS REV LETT, V76, P4285 4093 SNEPPEN K, 1992, PHYS REV LETT, V69, P3539 4094 SNEPPEN K, 1995, PHYSICA A, V221, P168 4095 SOCOLAR JES, 1993, PHYS REV E, V47, P2366 4096 SOLE RV, 1997, NATURE, V388, P764 4097 SORNETTE D, 1995, J PHYS I, V5, P325 4098 SORNETTE D, 1998, EUR PHYS J B, V1, P353 4099 SPASOJEVIC D, 1996, PHYS REV E, V54, P2531 4100 TAKAYASU H, 1989, PHYS REV LETT, V63, P2563 4101 TAKAYASU H, 1992, PHYS REV LETT, V68, P3060 4102 URBACH JS, 1995, PHYS REV LETT, V75, P276 4103 VERGELES M, 1995, PHYS REV LETT, V75, P1969 4104 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 4105 VESPIGNANI A, 1998, PHYS REV E, V57, P6345 4106 VESPIGNANI A, 1998, PHYS REV LETT, V81, P5676 4107 VICSEK T, 1992, FRACTAL GROWTH PHENO 4108 WEISS J, 1997, J PHYS CHEM B, V101, P6113 4109 WILKINSON D, 1983, J PHYS A-MATH GEN, V16, P3365 4110 ZAITSEV SI, 1992, PHYSICA A, V189, P411 4111 ZAPPERI S, 1997, NATURE, V388, P658 4112 ZAPPERI S, 1998, PHYS REV B, V58, P6353 4113 ZAPPERI S, 1999, PHYS REV E A, V59, P5049 4114 NR 128 4115 TC 84 4116 PU SOCIEDADE BRASILEIRA FISICA 4117 PI SAO PAULO 4118 PA CAIXA POSTAL 66328, 05315-970 SAO PAULO, BRAZIL 4119 SN 0103-9733 4120 J9 BRAZ J PHYS 4121 JI Braz. J. Phys. 4122 PD MAR 4123 PY 2000 4124 VL 30 4125 IS 1 4126 BP 27 4127 EP 41 4128 PG 15 4129 SC Physics, Multidisciplinary 4130 GA 301TB 4131 UT ISI:000086325400004 4132 ER 4133 4134 PT J 4135 AU Pastor-Satorras, R 4136 Vespignani, A 4137 TI Universality classes in directed sandpile models 4138 SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL 4139 LA English 4140 DT Letter 4141 ID SELF-ORGANIZED CRITICALITY; NOISE 4142 AB We perform large-scale numerical simulations of a directed version of 4143 the two-state stochastic sandpile model. Numerical results show that 4144 this stochastic model defines a new universality class with respect to 4145 the Abelian directed sandpile. The physical origin of the different 4146 critical behaviour has to be ascribed to the presence of multiple 4147 topplings in the stochastic model. These results provide new insight 4148 into the long-debated question of universality in Abelian and 4149 stochastic sandpiles. 4150 C1 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 4151 RP Pastor-Satorras, R, Abdus Salam Int Ctr Theoret Phys, POB 586, I-34100 4152 Trieste, Italy. 4153 CR BAK P, 1987, PHYS REV LETT, V59, P381 4154 CHESSA A, 1998, CONDMAT9811365 4155 CHESSA A, 1998, PHYS REV E, V57, R6421 4156 CHESSA A, 1999, COMPUT PHYS COMMUN, V121, P299 4157 CHESSA A, 1999, PHYS REV E A, V59, R12 4158 DEMENECH M, 1998, PHYS REV E A, V58, R2677 4159 DHAR D, 1989, PHYS REV LETT, V63, P1659 4160 DHAR D, 1999, PHYSICA A, V263, P4 4161 DIAZGUILERA A, 1992, PHYS REV A, V45, P8551 4162 DICKMAN R, 1998, PHYS REV E A, V57, P5095 4163 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 4164 GRASSBERGER P, 1995, PHYS LETT A, V200, P277 4165 HASTY J, 1998, PHYS REV LETT, V81, P1722 4166 JENSEN HJ, 1998, SELF ORG CRITICALITY 4167 KADANOFF LP, 1989, PHYS REV A, V39, P6524 4168 LAURITSEN KB, 1996, PHYS REV E, V54, P2483 4169 LAURITSEN KB, 1999, CONDMAT9903346 4170 LUBECK S, 1998, PHYS REV E A, V58, P2957 4171 MANNA SS, 1991, J PHYS A, V24, L363 4172 MILSHTEIN E, 1998, PHYS REV E, V58, P303 4173 PACZUSKI M, 1994, EUROPHYS LETT, V27, P97 4174 PACZUSKI M, 1996, PHYS REV LETT, V77, P111 4175 PASTORSATORRAS R, UNPUB 4176 TADIC B, 1997, PHYS REV LETT, V79, P1519 4177 TEBALDI C, 1999, CONDMAT9903270 4178 TEBALDI C, 1999, PHYS REV LETT, V83, P3952 4179 TSUCHIYA T, 1999, J PHYS A-MATH GEN, V32, P1629 4180 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 4181 VESPIGNANI A, 1998, PHYS REV E, V57, P6345 4182 VESPIGNANI A, 1998, PHYS REV LETT, V81, P5676 4183 NR 30 4184 TC 16 4185 PU IOP PUBLISHING LTD 4186 PI BRISTOL 4187 PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND 4188 SN 0305-4470 4189 J9 J PHYS-A-MATH GEN 4190 JI J. Phys. A-Math. Gen. 4191 PD JAN 28 4192 PY 2000 4193 VL 33 4194 IS 3 4195 BP L33 4196 EP L39 4197 PG 7 4198 SC Physics, Multidisciplinary; Physics, Mathematical 4199 GA 283AW 4200 UT ISI:000085254800001 4201 ER 4202 4203 PT J 4204 AU Chessa, A 4205 Vespignani, A 4206 Zapperi, S 4207 TI Critical exponents in stochastic sandpile models 4208 SO COMPUTER PHYSICS COMMUNICATIONS 4209 LA English 4210 DT Article 4211 ID SELF-ORGANIZED CRITICALITY; UPPER CRITICAL DIMENSION; UNIVERSALITY; 4212 BEHAVIOR 4213 AB We present large scale simulations of a stochastic sandpile model in 4214 two dimensions. We use momentum analysis to evaluate critical exponents 4215 and finite size scaling method to consistently test the obtained 4216 results. The general picture resulting from our analysis allows us to 4217 characterize the large scale behavior of the present model with great 4218 accuracy. (C) 1999 Elsevier Science B.V. All rights reserved. 4219 C1 Univ Cagliari, Dipartimento Fis, I-09124 Cagliari, Italy. 4220 Univ Cagliari, Unita INFM, I-09124 Cagliari, Italy. 4221 ICTP, Abdus Salam Int Ctr Theorect Phys, I-34100 Trieste, Italy. 4222 ESPCI, PMMH, F-75234 Paris 05, France. 4223 RP Chessa, A, Univ Cagliari, Dipartimento Fis, Via Osped 72, I-09124 4224 Cagliari, Italy. 4225 CR BAK P, 1987, PHYS REV LETT, V59, P381 4226 BENHUR A, 1996, PHYS REV E, V53, P1317 4227 CHESSA A, 1998, PHYS REV E, V57, R6241 4228 CORRAL A, 1997, PHYS REV E A, V55, P2434 4229 DEMENECH M, 1998, PHYS REV E A, V58, R2677 4230 DHAR D, CONDMAT9808047 4231 DIAZGUILERA A, 1994, EUROPHYS LETT, V26, P177 4232 DICKMAN R, 1998, PHYS REV E A, V57, P5095 4233 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 4234 LUBECK S, 1997, PHYS REV E A, V56, P5138 4235 LUBECK S, 1997, PHYS REV E, V55, P4095 4236 LUBECK S, 1997, PHYS REV E, V56, P1590 4237 MANNA SS, 1990, J STAT PHYS, V59, P509 4238 MANNA SS, 1991, J PHYS A, V24, L363 4239 MANNA SS, 1991, PHYSICA A, V179, P249 4240 MILSHTEIN E, 1998, PHYS REV E, V58, P303 4241 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 4242 PRIEZZHEV VB, 1996, PHYS REV LETT, V76, P2093 4243 VESPIGNANI A, CONDMAT9806249 4244 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 4245 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 4246 NR 21 4247 TC 16 4248 PU ELSEVIER SCIENCE BV 4249 PI AMSTERDAM 4250 PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS 4251 SN 0010-4655 4252 J9 COMPUT PHYS COMMUN 4253 JI Comput. Phys. Commun. 4254 PD SEP-OCT 4255 PY 1999 4256 VL 122 4257 SI Sp. Iss. SI 4258 BP 299 4259 EP 302 4260 PG 4 4261 SC Computer Science, Interdisciplinary Applications; Physics, Mathematical 4262 GA 263LP 4263 UT ISI:000084126400071 4264 ER 4265 4266 PT J 4267 AU Barrat, A 4268 Vespignani, A 4269 Zapperi, S 4270 TI Fluctuations and correlations in sandpile models 4271 SO PHYSICAL REVIEW LETTERS 4272 LA English 4273 DT Article 4274 ID SELF-ORGANIZED CRITICALITY; NON-BOLTZMANN FLUCTUATIONS; LATTICE 4275 THRESHOLD SYSTEMS; UPPER CRITICAL DIMENSION; NUMERICAL SIMULATIONS; 4276 AVALANCHES; EXPONENTS; DYNAMICS; EVENTS; NOISE 4277 AB We perform numerical simulations of the sandpile model for nonvanishing 4278 driving fields it and dissipation rates epsilon. Unlike simulations 4279 performed in the slow driving limit, the unique time scale present in 4280 our system allows us to measure unambiguously the response and 4281 correlation functions. We discuss the dynamic scaling of the model and 4282 show that fluctuation-dissipation relations are not obeyed in this 4283 system. 4284 C1 Univ Paris 11, Phys Theor Lab, UMR 8627, F-91405 Orsay, France. 4285 Int Ctr Theoret Phys, I-34100 Trieste, Italy. 4286 Ecole Super Phys & Chim Ind Ville Paris, PMMH, F-75231 Paris, France. 4287 RP Barrat, A, Univ Paris 11, Phys Theor Lab, UMR 8627, Batiment 210, 4288 F-91405 Orsay, France. 4289 CR BAK P, 1987, PHYS REV LETT, V59, P381 4290 BAK P, 1988, PHYS REV A, V38, P364 4291 BARRAT A, IN PRESS 4292 CHESSA A, 1998, PHYS REV E, V57, R6241 4293 CHESSA A, 1999, PHYS REV E A, V59, R12 4294 CUGLIANDOLO LF, 1997, PHYS REV E, V55, P3898 4295 DEMENECH M, 1998, PHYS REV E A, V58, R2677 4296 DHAR D, 1990, PHYS REV LETT, V64, P1613 4297 DIAZGUILERA A, 1992, PHYS REV A, V45, P8551 4298 DICKMAN R, 1998, PHYS REV E A, V57, P5095 4299 GIACOMETTI A, 1998, PHYS REV E, V58, P247 4300 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 4301 HWA T, 1992, PHYS REV A, V45, P7002 4302 KUTNJAKURBANC B, 1996, PHYS REV E, V54, P6109 4303 LAURITSEN KB, IN PRESS 4304 LUBECK S, 1997, PHYS REV E A, V56, P5138 4305 LUBECK S, 1997, PHYS REV E, V55, P4095 4306 LUBECK S, 1997, PHYS REV E, V56, P1590 4307 MANNA SS, 1990, J STAT PHYS, V59, P509 4308 MANNA SS, 1991, J PHYS A, V24, L363 4309 MANNA SS, 1991, PHYSICA A, V179, P249 4310 MONTAKHAB A, 1998, PHYS REV E A, V58, P5608 4311 NARAYAN O, 1994, PHYS REV B, V49, P244 4312 PACZUSKI M, 1996, PHYS REV LETT, V77, P111 4313 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 4314 PRIEZZHEV VB, 1994, J STAT PHYS, V74, P955 4315 RUNDLE JB, 1995, PHYS REV LETT, V75, P1658 4316 RUNDLE JB, 1997, PHYS REV LETT, V78, P3798 4317 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 4318 VESPIGNANI A, 1998, PHYS REV E, V57, P6345 4319 VESPIGNANI A, 1998, PHYS REV LETT, V81, P5676 4320 XU HJ, 1997, PHYS REV LETT, V78, P3797 4321 ZAPPERI S, 1995, PHYS REV LETT, V75, P4071 4322 NR 33 4323 TC 6 4324 PU AMERICAN PHYSICAL SOC 4325 PI COLLEGE PK 4326 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 4327 SN 0031-9007 4328 J9 PHYS REV LETT 4329 JI Phys. Rev. Lett. 4330 PD SEP 6 4331 PY 1999 4332 VL 83 4333 IS 10 4334 BP 1962 4335 EP 1965 4336 PG 4 4337 SC Physics, Multidisciplinary 4338 GA 232WK 4339 UT ISI:000082392800016 4340 ER 4341 4342 PT J 4343 AU Zapperi, S 4344 Ray, P 4345 Stanley, HE 4346 Vespignani, A 4347 TI Analysis of damage clusters in fracture processes 4348 SO PHYSICA A 4349 LA English 4350 DT Article 4351 DE fracture and cracks; phase transitions; avalanches 4352 ID SELF-ORGANIZED CRITICALITY; ACOUSTIC-EMISSION; ELECTRICAL BREAKDOWN; 4353 BURST AVALANCHES; NUCLEATION; MODELS; MEDIA; PRECURSORS; TRANSITION; 4354 BEHAVIOR 4355 AB We present numerical simulations of two-dimensional models of electric 4356 breakdown and fracture in disordered systems subject to an increasing 4357 external stress. We provide a geometrical characterization of the 4358 damage by studying the scaling behavior of connected bonds clusters, 4359 The average cluster size and the lattice conductivity show features 4360 characteristic of a first order phase transition. The obtained results 4361 are discussed within the spinodal nucleation scenario recently proposed 4362 for fractures. (C) 1999 Published by Elsevier Science B.V. All rights 4363 reserved. 4364 C1 Int Ctr Theoret Phys, I-34100 Trieste, Italy. 4365 Ecole Super Phys & Chim Ind, PMMH, F-75231 Paris 05, France. 4366 Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. 4367 Boston Univ, Dept Phys, Boston, MA 02215 USA. 4368 RP Vespignani, A, Int Ctr Theoret Phys, POB 586, I-34100 Trieste, Italy. 4369 CR BARDHAN KK, 1994, NONLINEARITY BREAKDO 4370 CANNELLI G, 1993, PHYS REV LETT, V70, P3923 4371 CHAKRABARTI BK, 1997, STAT PHYSICS FRACTUR 4372 DEARCANGELIS L, 1985, J PHYS LETT, V46, L585 4373 DEARCANGELIS L, 1989, PHYS REV B, V39, P2678 4374 DIODATI P, 1991, PHYS REV LETT, V67, P2239 4375 DUXBURY PM, 1986, PHYS REV LETT, V57, P1052 4376 ENGLMAN R, 1990, PHYSICA A, V168, P665 4377 GARCIMARTIN A, 1997, PHYS REV LETT, V79, P3202 4378 GOLUBOVIC L, 1991, PHYS REV A, V43, P5223 4379 GOLUBOVIC L, 1995, PHYS REV E A, V51, P2799 4380 GRIFFITH AA, 1920, PHILOS T R SOC A, V221, P163 4381 GUARINO A, 1998, EUR PHYS J B, V6, P13 4382 HANSEN A, 1994, PHYS LETT A, V184, P394 4383 HEERMANN DW, 1982, PHYS REV LETT, V49, P1262 4384 HEMMER PC, 1992, J APPL MECH-T ASME, V59, P909 4385 KAHNG B, 1988, PHYS REV B, V37, P7625 4386 KLOSTER M, 1997, PHYS REV E A, V56, P2615 4387 LEUNG KT, 1997, EUROPHYS LETT, V38, P589 4388 LEUNG KT, 1998, PHYS REV LETT, V80, P1916 4389 MAES C, 1998, PHYS REV B, V57, P4987 4390 MONETTE L, 1994, INT J MOD PHYS B, V8, P1417 4391 PETRI A, 1994, PHYS REV LETT, V73, P3423 4392 RAY P, 1996, PHYSICA A, V229, P26 4393 RAY TS, 1990, J STAT PHYS, V61, P891 4394 ROUX S, 1988, J STAT PHYS, V52, P237 4395 SELINGER RLB, 1991, J CHEM PHYS, V95, P9128 4396 UNGER C, 1985, PHYS REV B, V31, P6127 4397 WEISS J, 1997, J PHYS CHEM B, V101, P6113 4398 ZAPPERI S, 1997, NATURE, V388, P658 4399 ZAPPERI S, 1997, PHYS REV LETT, V78, P1408 4400 ZAPPERI S, 1999, PHYS REV E A, V59, P5049 4401 NR 32 4402 TC 5 4403 PU ELSEVIER SCIENCE BV 4404 PI AMSTERDAM 4405 PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS 4406 SN 0378-4371 4407 J9 PHYSICA A 4408 JI Physica A 4409 PD AUG 1 4410 PY 1999 4411 VL 270 4412 IS 1-2 4413 BP 57 4414 EP 62 4415 PG 6 4416 SC Physics, Multidisciplinary 4417 GA 231PQ 4418 UT ISI:000082319300010 4419 ER 4420 4421 PT J 4422 AU Ivashkevich, EV 4423 Povolotsky, AM 4424 Vespignani, A 4425 Zapperi, S 4426 TI Dynamical real space renormalization group applied to sandpile models 4427 SO PHYSICAL REVIEW E 4428 LA English 4429 DT Article 4430 ID SELF-ORGANIZED CRITICALITY; FOREST-FIRE MODEL; 2-DIMENSIONAL ABELIAN 4431 SANDPILE; HEIGHT CORRELATIONS; CRITICAL EXPONENTS; CRITICAL-BEHAVIOR; 4432 ABSORBING-STATE; UNIVERSALITY; AVALANCHES; AUTOMATON 4433 AB A general framework for the renormalization group analysis of 4434 self-organized critical sandpile models is formulated. The usual real 4435 space renormalization scheme for lattice models when applied to 4436 nonequilibrium dynamical models must be supplemented by feedback 4437 relations coming from the stationarity conditions. On the basis of 4438 these ideas the dynamically driven renormalization group is applied to 4439 describe the boundary and bulk critical behavior of sandpile models. A 4440 detailed description of the branching nature of sandpile avalanches is 4441 given in terms of the generating functions of the underlying branching 4442 process. [S1063-651X(99)06006-7]. 4443 C1 Joint Inst Nucl Res, Bogoliubov Lab Theoret Phys, Dubna 141980, Russia. 4444 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 4445 ESPCI, PMMH, F-75234 Paris, France. 4446 RP Ivashkevich, EV, Joint Inst Nucl Res, Bogoliubov Lab Theoret Phys, 4447 Dubna 141980, Russia. 4448 CR BAK P, 1988, PHYS REV A, V38, P364 4449 BAK P, 1990, PHYS LETT A, V147, P297 4450 BAK P, 1993, FRACTALS DISORDERED, V2 4451 BENHUR A, 1996, PHYS REV E, V53, P1317 4452 BENHUR A, 1996, PHYS REV E, V54, P1426 4453 CARDY JL, 1972, PHASE TRANSITION CRI, V11 4454 DEOLIVEIRA MJ, 1997, PHYS REV E A, V55, P6377 4455 DHAR D, 1990, PHYS REV LETT, V64, P1613 4456 DICKMAN R, 1988, PHYS REV A, V38, P2588 4457 DICKMAN R, 1998, PHYS REV E A, V57, P5095 4458 DOMB C, 1972, PHASE TRANSITION CRI, V1 4459 DOMB C, 1983, PHASE TRANSITION CRI, V7 4460 DROSSEL B, 1992, PHYS REV LETT, V69, P1629 4461 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 4462 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 4463 HASTY J, 1997, J STAT PHYS, V86, P1179 4464 HASTY J, 1998, PHYS REV LETT, V81, P1722 4465 IVASHKEVICH EV, 1994, J PHYS A, V27, L585 4466 IVASHKEVICH EV, 1994, J PHYS A-MATH GEN, V27, P3643 4467 IVASHKEVICH EV, 1994, PHYSICA A, V209, P347 4468 IVASHKEVICH EV, 1996, PHYS REV LETT, V76, P3368 4469 KATZ S, 1983, PHYS REV B, V28, P1655 4470 LORETO V, 1995, PHYS REV LETT, V75, P465 4471 LUBECK S, 1997, PHYS REV E, V55, P4095 4472 LUBECK S, 1997, PHYS REV E, V56, P1590 4473 MAJUMDAR SN, 1991, J PHYS A, V24, L357 4474 MANDELBROT BB, 1983, FRACTAL GEOMETRY NAT 4475 MANNA SS, 1991, J PHYS A, V24, L363 4476 MILSHTEIN E, 1998, PHYS REV E, V58, P303 4477 NIEMEIJER T, 1972, PHASE TRANSITION CRI, V6 4478 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 4479 PRIEZZHEV VB, 1994, J STAT PHYS, V74, P955 4480 PRIEZZHEV VB, 1996, PHYS REV LETT, V76, P2093 4481 SCHMITTMANN B, 1972, PHASE TRANSITION CRI, V17 4482 STELLA AL, 1995, PHYS REV E A, V52, P72 4483 TOME T, 1997, PHYS REV E, V55, P4000 4484 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 4485 VESPIGNANI A, 1996, PHYS REV LETT, V77, P4560 4486 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 4487 VESPIGNANI A, 1998, PHYS REV E, V57, P6345 4488 VICSEK T, 1992, FRACTAL GROWTH PHENO 4489 ZHANG YC, 1989, PHYS REV LETT, V63, P470 4490 NR 42 4491 TC 4 4492 PU AMERICAN PHYSICAL SOC 4493 PI COLLEGE PK 4494 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 4495 SN 1063-651X 4496 J9 PHYS REV E 4497 JI Phys. Rev. E 4498 PD AUG 4499 PY 1999 4500 VL 60 4501 IS 2 4502 PN Part A 4503 BP 1239 4504 EP 1251 4505 PG 13 4506 SC Physics, Fluids & Plasmas; Physics, Mathematical 4507 GA 230CU 4508 UT ISI:000082234900023 4509 ER 4510 4511 PT J 4512 AU Zapperi, S 4513 Ray, P 4514 Stanley, HE 4515 Vespignani, A 4516 TI Comment on "first-order transition in the breakdown of disordered 4517 media" - Zapperi et al. reply 4518 SO PHYSICAL REVIEW LETTERS 4519 LA English 4520 DT Article 4521 ID FRACTURE PRECURSORS 4522 C1 ESPCI, PMMH, F-75231 Paris 05, France. 4523 Inst Math Sci, Chennai 600113, India. 4524 Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. 4525 Boston Univ, Dept Phys, Boston, MA 02215 USA. 4526 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 4527 RP Zapperi, S, ESPCI, PMMH, 10 Rue Vauquelin, F-75231 Paris 05, France. 4528 CR CALDARELLI G, 1999, PHYS REV LETT, V83, P1483 4529 DUXBURY PM, 1986, PHYS REV LETT, V57, P1052 4530 GARCIMARTIN A, 1997, PHYS REV LETT, V79, P3202 4531 GUARINO A, 1998, EUR PHYS J B, V6, P13 4532 RAISANEN VI, 1998, PHYS REV B, V58, P14288 4533 ZAPPERI S, 1997, PHYS REV LETT, V78, P1408 4534 ZAPPERI S, 1999, PHYS REV E A, V59, P5049 4535 NR 7 4536 TC 0 4537 PU AMERICAN PHYSICAL SOC 4538 PI COLLEGE PK 4539 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 4540 SN 0031-9007 4541 J9 PHYS REV LETT 4542 JI Phys. Rev. Lett. 4543 PD AUG 16 4544 PY 1999 4545 VL 83 4546 IS 7 4547 BP 1484 4548 EP 1484 4549 PG 1 4550 SC Physics, Multidisciplinary 4551 GA 227EY 4552 UT ISI:000082066600054 4553 ER 4554 4555 PT J 4556 AU Zapperi, S 4557 Ray, P 4558 Stanley, HE 4559 Vespignani, A 4560 TI Avalanches in breakdown and fracture processes 4561 SO PHYSICAL REVIEW E 4562 LA English 4563 DT Article 4564 ID SELF-ORGANIZED CRITICALITY; ACOUSTIC-EMISSION; DIELECTRIC-BREAKDOWN; 4565 ELECTRICAL BREAKDOWN; BURST AVALANCHES; PHASE-TRANSITION; FUSE 4566 NETWORKS; NUCLEATION; DISORDER; DYNAMICS 4567 AB We investigate the breakdown of disordered networks under the action of 4568 an increasing external-mechanical or electrical-force. We perform a 4569 mean-field analysis and estimate scaling exponents for the approach to 4570 the instability. By simulating two-dimensional models of electric 4571 breakdown and fracture we observe that the breakdown is preceded by 4572 avalanche events. The avalanches can be described by scaling laws, and 4573 the estimated values of the exponents are consistent with those found 4574 in mean-field theory. The breakdown point is characterized by a 4575 discontinuity in the macroscopic properties of the material, such as 4576 conductivity or elasticity, indicative of a first-order transition. The 4577 scaling laws suggest an analogy with the behavior expected in spinodal 4578 nucleation. [S1063-651X(99)09205-3]. 4579 C1 Ecole Super Phys & Chim Ind, PMMH, F-75231 Paris 05, France. 4580 Inst Math Sci, Madras 600113, Tamil Nadu, India. 4581 Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. 4582 Boston Univ, Dept Phys, Boston, MA 02215 USA. 4583 Abdus Salam Int Ctr Theoret Phys, ICTP, I-34100 Trieste, Italy. 4584 RP Zapperi, S, Ecole Super Phys & Chim Ind, PMMH, 10 Rue Vauquelin, 4585 F-75231 Paris 05, France. 4586 CR ACHARYYA M, 1996, PHYS REV E A, V53, P140 4587 ACHARYYA M, 1996, PHYSICA A, V224, P287 4588 BARDHAN KK, 1994, NONLINEARITY BREAKDO 4589 BUCHEL A, 1996, PHYS REV LETT, V77, P1520 4590 CALDARELLI G, 1996, PHYS REV LETT, V77, P2503 4591 CANNELLI G, 1993, PHYS REV LETT, V70, P3923 4592 CHAKRABARTI BK, 1997, STAT PHYSICS FRACTUR 4593 CILIBERTO S, 1994, J PHYS I, V4, P223 4594 DAHMEN K, 1996, PHYS REV B, V53, P14872 4595 DANIELS HE, 1945, PROC R SOC LON SER-A, V183, P405 4596 DEARCANGELIS L, 1985, J PHYS LETT, V46, L585 4597 DEARCANGELIS L, 1989, PHYS REV B, V39, P2678 4598 DIODATI P, 1991, PHYS REV LETT, V67, P2239 4599 DUXBURY PM, 1986, PHYS REV LETT, V57, P1052 4600 ENGLMAN R, 1990, PHYSICA A, V168, P665 4601 FIELD S, 1995, PHYS REV LETT, V74, P1206 4602 GARCIMARTIN A, 1997, PHYS REV LETT, V79, P3202 4603 GOLUBOVIC L, 1991, PHYS REV A, V43, P5223 4604 GRIFFITH AA, 1920, PHILOS T R SOC A, V221, P163 4605 GUARINO A, 1998, EUR PHYS J B, V6, P13 4606 GUNTON JD, 1983, PHASE TRANSITIONS CR, V8 4607 GUTENBERG B, 1944, B SEISMOL SOC AM, V34, P185 4608 HANSEN A, 1994, PHYS LETT A, V184, P394 4609 HANSEN A, 1994, TRENDS STAT PHYS, V1, P213 4610 HEERMANN DW, 1982, PHYS REV LETT, V49, P1262 4611 HEMMER PC, 1992, J APPL MECH-T ASME, V59, P909 4612 HERRMANN HJ, 1990, STAT MODELS FRACTURE 4613 KAHNG B, 1988, PHYS REV B, V37, P7625 4614 KIRKPATRICK S, 1973, REV MOD PHYS, V45, P574 4615 KLOSTER M, 1997, PHYS REV E A, V56, P2615 4616 LEUNG KT, 1997, EUROPHYS LETT, V38, P589 4617 LIEBOWITZ H, 1968, FRACTURE ADV TREATIS, V1 4618 MAES C, 1998, PHYS REV B, V57, P4987 4619 MONETTE L, 1992, PHYS REV LETT, V63, P2336 4620 MONETTE L, 1994, INT J MOD PHYS B, V8, P1417 4621 PETRI A, 1994, PHYS REV LETT, V73, P3423 4622 PHOENIX SL, 1973, ADV APPL PROBAB, V5, P200 4623 PRESS WH, 1991, COMPUT PHYS, V5, P514 4624 RAISANEN VI, 1998, PHYS REV B, V58, P14288 4625 RAY P, 1996, PHYSICA A, V229, P26 4626 RAY TS, 1990, J STAT PHYS, V61, P891 4627 ROUX S, 1988, J STAT PHYS, V52, P237 4628 RUNDLE J, 1998, PHYS REV LETT, V80, P5698 4629 RUNDLE JB, 1989, PHYS REV LETT, V63, P171 4630 RUNDLE JB, 1995, P SANT FE I WORKSH R 4631 RUNDLE JB, 1996, PHYS REV LETT, V76, P4285 4632 SELINGER RLB, 1991, J CHEM PHYS, V95, P9128 4633 SELINGER RLB, 1991, PHYS REV A, V43, P4396 4634 SETHNA JP, 1993, PHYS REV LETT, V70, P3347 4635 SORNETTE D, 1998, EUR PHYS J B, V1, P353 4636 SUKI B, 1994, NATURE, V368, P615 4637 THOMPSON AH, 1987, PHYS REV LETT, V58, P29 4638 TZSCHICHHOLZ F, 1995, PHYS REV E, V51, P1961 4639 UNGER C, 1984, PHYS REV B, V29, P2698 4640 UNGER C, 1985, PHYS REV B, V31, P6127 4641 VASCONCELOS GL, 1996, PHYS REV LETT, V76, P4865 4642 WANG ZG, 1991, PHYS REV B, V44, P378 4643 WEISS J, 1997, J PHYS CHEM B, V101, P6113 4644 ZAPPERI S, 1997, NATURE, V388, P658 4645 ZAPPERI S, 1997, PHYS REV LETT, V78, P1408 4646 ZAPPERI S, 1998, PHYS REV B, V58, P6353 4647 NR 61 4648 TC 47 4649 PU AMERICAN PHYSICAL SOC 4650 PI COLLEGE PK 4651 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 4652 SN 1063-651X 4653 J9 PHYS REV E 4654 JI Phys. Rev. E 4655 PD MAY 4656 PY 1999 4657 VL 59 4658 IS 5 4659 PN Part A 4660 BP 5049 4661 EP 5057 4662 PG 9 4663 SC Physics, Fluids & Plasmas; Physics, Mathematical 4664 GA 197TX 4665 UT ISI:000080382700050 4666 ER 4667 4668 PT J 4669 AU Munoz, MA 4670 Dickman, R 4671 Vespignani, A 4672 Zapperi, S 4673 TI Avalanche and spreading exponents in systems with absorbing states 4674 SO PHYSICAL REVIEW E 4675 LA English 4676 DT Article 4677 ID SELF-ORGANIZED CRITICALITY; SURFACE-REACTION MODEL; ANNIHILATING 4678 RANDOM-WALKS; BAK-SNEPPEN MODEL; DIRECTED PERCOLATION; 4679 CRITICAL-BEHAVIOR; FIELD-THEORY; PHASE-TRANSITIONS; PUNCTUATED 4680 EQUILIBRIUM; INFINITE NUMBERS 4681 AB We present generic scaling laws relating spreading critical exponents 4682 and avalanche exponents (in the sense of self-organized criticality) in 4683 general systems with absorbing states. Using these scaling laws we 4684 present a collection of the state-of-the-art exponents for directed 4685 percolation, dynamical percolation, and other universality classes. 4686 This collection of results should help to elucidate the connections of 4687 self-organized criticality and systems with absorbing states. In 4688 particular, some nonuniversality in avalanche exponents is predicted 4689 for systems with many absorbing states. [S1063-651X(99)06205-4]. 4690 C1 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 4691 Univ La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. 4692 Univ La Sapienza, Unita INFM, I-00185 Rome, Italy. 4693 Univ Fed Santa Catarina, Dept Fis, BR-88040900 Florianopolis, SC, Brazil. 4694 Ecole Super Phys & Chim Ind, PMMH, F-75231 Paris 05, France. 4695 RP Munoz, MA, Abdus Salam Int Ctr Theoret Phys, POB 586, I-34100 Trieste, 4696 Italy. 4697 CR ADLER J, 1987, PHYS REV B, V35, P7046 4698 ADLER J, 1988, PHYS REV B, V37, P7529 4699 BAK P, 1987, PHYS REV LETT, V59, P381 4700 BAK P, 1993, PHYS REV LETT, V71, P4083 4701 BARABASI AL, 1995, FRACTAL CONCEPTS SUR 4702 BARABASI AL, 1996, PHYS REV LETT, V76, P1481 4703 BUNDE A, 1991, FRACTALS DISORDERED 4704 CARDY J, 1996, PHYS REV LETT, V77, P4780 4705 CARDY JL, 1985, J PHYS A, V18, L267 4706 CHESSA A, 1999, PHYS REV E A, V59, R12 4707 CLAR S, 1995, PHYS REV LETT, V75, P2722 4708 DEUTSCHER G, 1983, ANN ISRAEL PHYSICAL, V5 4709 DICKMAN R, 1998, PHYS REV E A, V57, P5095 4710 DOMANY E, 1984, PHYS REV LETT, V53, P311 4711 FROJDH P, 1998, J PHYS A-MATH GEN, V31, P2311 4712 GRASSBERGER P, CONDMAT9808095 4713 GRASSBERGER P, 1979, ANN PHYS-NEW YORK, V122, P373 4714 GRASSBERGER P, 1982, Z PHYS B CON MAT, V47, P365 4715 GRASSBERGER P, 1983, MATH BIOSCI, V63, P157 4716 GRASSBERGER P, 1985, J PHYS A, V18, L215 4717 GRASSBERGER P, 1995, J STAT PHYS, V79, P13 4718 GRASSBERGER P, 1995, PHYS LETT A, V200, P277 4719 HARRIS TE, 1974, ANN PROBAB, V2, P969 4720 HAVLIN S, 1984, J PHYS A-MATH GEN, V17, L427 4721 JANSSEN HK, 1981, Z PHYS B CON MAT, V42, P151 4722 JANSSEN HK, 1985, Z PHYS B CON MAT, V58, P311 4723 JENSEN I, 1990, PHYS REV A, V41, P3411 4724 JENSEN I, 1992, PHYS REV A, V45, R563 4725 JENSEN I, 1993, PHYS REV E, V48, P1710 4726 JENSEN I, 1993, PHYS REV LETT, V70, P1465 4727 JENSEN I, 1994, INT J MOD PHYS B, V8, P3299 4728 JENSEN I, 1994, PHYS REV E, V50, P3623 4729 JENSEN I, 1996, J PHYS A-MATH GEN, V29, P7013 4730 JOVANOVIC B, 1994, PHYS REV E, V50, P2403 4731 KERTESZ J, 1989, PHYS REV LETT, V62, P2571 4732 KIM MH, 1994, PHYS REV LETT, V73, P2579 4733 LAURITSEN KB, 1997, PHYSICA A, V247, P1 4734 LAURITSEN KB, 1998, PHYS REV LETT, V81, P2104 4735 LIGGETT TM, 1985, INTERACTING PARTICLE 4736 MARRO J, 1997, LECT NOTE PHYS, V493, P223 4737 MASLOV S, 1995, PHYS REV LETT, V74, P562 4738 MENDES JFF, 1994, J PHYS A-MATH GEN, V27, P3019 4739 MUNOZ MA, REPORT 4740 MUNOZ MA, 1996, PHYS REV LETT, V76, P451 4741 MUNOZ MA, 1997, PHYS REV E A, V56, P5101 4742 MUNOZ MA, 1997, PHYSICA D, V103, P485 4743 MUNOZ MA, 1998, J STAT PHYS, V91, P541 4744 PACZUSKI M, 1994, EUROPHYS LETT, V27, P97 4745 PACZUSKI M, 1996, PHYS REV E A, V53, P414 4746 SORNETTE D, 1996, PHYS REV E A, V54, P3334 4747 TAKAYASU H, 1992, PHYS REV LETT, V68, P3060 4748 VESPIGNANI A, 1998, PHYS REV LETT, V81, P5676 4749 VOIGT CA, 1997, PHYS REV E, V56, P6241 4750 ZIFF RM, 1986, PHYS REV LETT, V56, P2553 4751 NR 54 4752 TC 50 4753 PU AMERICAN PHYSICAL SOC 4754 PI COLLEGE PK 4755 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 4756 SN 1063-651X 4757 J9 PHYS REV E 4758 JI Phys. Rev. E 4759 PD MAY 4760 PY 1999 4761 VL 59 4762 IS 5 4763 PN Part B 4764 BP 6175 4765 EP 6179 4766 PG 5 4767 SC Physics, Fluids & Plasmas; Physics, Mathematical 4768 GA 197TZ 4769 UT ISI:000080382900084 4770 ER 4771 4772 PT J 4773 AU Chessa, A 4774 Stanley, HE 4775 Vespignani, A 4776 Zapperi, S 4777 TI Universality in sandpiles 4778 SO PHYSICAL REVIEW E 4779 LA English 4780 DT Article 4781 ID SELF-ORGANIZED CRITICALITY; MODEL; NOISE 4782 AB We perform extensive numerical simulations of different versions of the 4783 sandpile model. We find that previous claims about universality classes 4784 are unfounded, since the method previously employed to analyze the data 4785 suffered from a systematic bias. We identify the correct scaling 4786 behavior and provide evidences suggesting that sandpiles with 4787 stochastic and deterministic toppling rules belong to the same 4788 universality class. [S1063-651X(99)50701-0]. 4789 C1 Univ Cagliari, Dipartimento Fis, I-09124 Cagliari, Italy. 4790 Univ Cagliari, Unita INFM, I-09124 Cagliari, Italy. 4791 Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. 4792 Boston Univ, Dept Phys, Boston, MA 02215 USA. 4793 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 4794 Ecole Super Phys & Chim Ind Ville Paris, PMMH, F-75231 Paris 05, France. 4795 RP Chessa, A, Univ Cagliari, Dipartimento Fis, Via Osped 72, I-09124 4796 Cagliari, Italy. 4797 CR AMARAL LAN, 1997, PHYS REV E A, V56, P231 4798 BAK P, 1987, PHYS REV LETT, V59, P381 4799 BENHUR A, 1996, PHYS REV E, V53, P1317 4800 CHESSA A, 1998, PHYS REV E, V57, R6241 4801 CHRISTENSEN K, 1991, J STAT PHYS, V63, P653 4802 CILIBERTO S, 1994, J PHYS I, V4, P223 4803 DEMENECH M, 1998, PHYS REV E A, V58, R2677 4804 DHAR D, 1989, PHYS REV LETT, V63, P1659 4805 DIAZGUILERA A, 1994, EUROPHYS LETT, V26, P177 4806 DICKMAN R, 1998, PHYS REV E A, V57, P5095 4807 DURIN G, 1995, FRACTALS, V3, P351 4808 FIELD S, 1995, PHYS REV LETT, V74, P1206 4809 GARCIMARTIN A, 1997, PHYS REV LETT, V79, P3202 4810 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 4811 GUTENBERG B, 1956, ANN GEOFIS, V9, P1 4812 LUBECK S, 1997, PHYS REV E A, V56, P5138 4813 LUBECK S, 1997, PHYS REV E, V55, P4095 4814 LUBECK S, 1997, PHYS REV E, V56, P1590 4815 MANNA SS, 1991, J PHYS A, V24, L363 4816 MILSHTEIN E, CONDMAT9805206 4817 MILSHTEIN E, 1998, PHYS REV E, V58, P303 4818 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 4819 SPASOJEVIC D, 1996, PHYS REV E, V54, P2531 4820 VESPIGNANI A, CONDMAT9806249 4821 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 4822 VESPIGNANI A, 1998, PHYS REV E, V57, P6345 4823 ZHANG YC, 1989, PHYS REV LETT, V63, P470 4824 NR 27 4825 TC 31 4826 PU AMERICAN PHYSICAL SOC 4827 PI COLLEGE PK 4828 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 4829 SN 1063-651X 4830 J9 PHYS REV E 4831 JI Phys. Rev. E 4832 PD JAN 4833 PY 1999 4834 VL 59 4835 IS 1 4836 PN Part A 4837 BP R12 4838 EP R15 4839 PG 4 4840 SC Physics, Fluids & Plasmas; Physics, Mathematical 4841 GA 158JH 4842 UT ISI:000078111900004 4843 ER 4844 4845 PT J 4846 AU Vespignani, A 4847 Dickman, R 4848 Munoz, MA 4849 Zapperi, S 4850 TI Driving, conservation, and absorbing states in sandpiles 4851 SO PHYSICAL REVIEW LETTERS 4852 LA English 4853 DT Article 4854 ID SELF-ORGANIZED CRITICALITY; CRITICAL-BEHAVIOR; PHASE-TRANSITIONS; 4855 MODEL; EXPONENTS; LATTICE 4856 AB We use a phenomenological field theory, reflecting the symmetries and 4857 conservation laws of sandpiles, to compare the driven dissipative 4858 sandpile, widely studied in the context of self-organized criticality, 4859 with the corresponding fixed-energy model. The latter displays an 4860 absorbing-state phase transition with upper critical dimension d(c) = 4861 4. We show that the driven model exhibits a fundamentally different 4862 approach to the critical point, and compute a subset of critical 4863 exponents. We present numerical simulations in support of our 4864 theoretical predictions. 4865 C1 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 4866 Univ Fed Santa Catarina, Dept Fis, BR-88040900 Florianopolis, SC, Brazil. 4867 Univ Rome La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. 4868 Univ Rome La Sapienza, Unita INFM, I-00185 Rome, Italy. 4869 ESPCI, PMMH, F-75231 Paris 05, France. 4870 RP Vespignani, A, Abdus Salam Int Ctr Theoret Phys, POB 586, I-34100 4871 Trieste, Italy. 4872 CR BAK P, 1987, PHYS REV LETT, V59, P381 4873 BARABASI AL, 1995, FRACTAL CONCEPTS SUR 4874 CARDY J, 1996, PHYS REV LETT, V77, P4780 4875 CHESSA A, CONDMAT9808263 4876 CHESSA A, 1998, PHYS REV E, V57, R6241 4877 DHAR D, CONDMAT9808047 4878 DHAR D, 1990, PHYS REV LETT, V64, P1613 4879 DIAZGUILERA A, 1994, EUROPHYS LETT, V26, P177 4880 DICKMAN R, 1996, NONEQUILIBRIUM STAT 4881 DICKMAN R, 1998, PHYS REV E A, V57, P5095 4882 GRASSBERGER P, COMMUNICATION 4883 GRASSBERGER P, 1979, ANN PHYS-NEW YORK, V122, P373 4884 GRASSBERGER P, 1982, Z PHYS B CON MAT, V47, P365 4885 GRASSBERGER P, 1995, PHYS LETT A, V200, P277 4886 GRINSTEIN G, 1995, NATO ASI B, V344 4887 HARRIS TE, 1974, ANN PROBAB, V2, P969 4888 HARRIS TE, 1989, THEORY BRANCHING PRO 4889 JENSEN I, 1993, PHYS REV LETT, V70, P1465 4890 KINZEL W, 1985, Z PHYS B CON MAT, V58, P229 4891 LAURITSEN KB, COMMUNICATION 4892 LUBECK S, 1997, PHYS REV E, V55, P4095 4893 LUBECK S, 1998, PHYS REV E A, V58, P2957 4894 MANNA SS, 1991, J PHYS A, V24, L363 4895 MARRO J, 1998, NONEQUILIBRIUM PHASE 4896 MILSHTEIN E, 1998, PHYS REV E, V58, P303 4897 MUNOZ MA, 1996, PHYS REV LETT, V76, P451 4898 MUNOZ MA, 1998, J STAT PHYS, V91, P541 4899 PACZUSKI M, 1994, EUROPHYS LETT, V27, P97 4900 SORNETTE D, 1995, J PHYS I, V5, P325 4901 TANG C, 1988, PHYS REV LETT, V60, P2347 4902 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 4903 NR 31 4904 TC 63 4905 PU AMERICAN PHYSICAL SOC 4906 PI COLLEGE PK 4907 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 4908 SN 0031-9007 4909 J9 PHYS REV LETT 4910 JI Phys. Rev. Lett. 4911 PD DEC 21 4912 PY 1998 4913 VL 81 4914 IS 25 4915 BP 5676 4916 EP 5679 4917 PG 4 4918 SC Physics, Multidisciplinary 4919 GA 150HT 4920 UT ISI:000077659500050 4921 ER 4922 4923 PT J 4924 AU Chessa, A 4925 Marinari, E 4926 Vespignani, A 4927 Zapperi, S 4928 TI Mean-field behavior of the sandpile model below the upper critical 4929 dimension 4930 SO PHYSICAL REVIEW E 4931 LA English 4932 DT Article 4933 ID SELF-ORGANIZED CRITICALITY 4934 AB We present results of large scale numerical simulations of the Bak, 4935 Tang, and Wiesenfeld [Phys. Rev. Lett. 59, 381 (1987); Phys. Rev. A 38, 4936 364 (1988)] sandpile model. We analyze the critical behavior of the 4937 model in Euclidean dimensions 2 less than or equal to d less than or 4938 equal to 6. We consider a dissipative generalization of the model and 4939 study the avalanche size and duration distributions for different 4940 values of the lattice size and dissipation. We find that the scaling 4941 exponents in d=4 significantly differ from mean-field predictions, thus 4942 Suggesting an upper critical dimension d(c)greater than or equal to 5. 4943 Using the relations among the dissipation rate epsilon and the finite 4944 lattice size L, we find that a subset of the exponents displays 4945 mean-field values below the upper critical dimensions. This behavior is 4946 explained in terms of conservation laws. 4947 C1 Univ Cagliari, Dipartimento Fis, I-09124 Cagliari, Italy. 4948 INFM, Sez Cagliari, I-09124 Cagliari, Italy. 4949 INFN, Sez Cagliari, I-09124 Cagliari, Italy. 4950 Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. 4951 Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. 4952 Boston Univ, Dept Phys, Boston, MA 02215 USA. 4953 RP Chessa, A, Univ Cagliari, Dipartimento Fis, Via Osped 72, I-09124 4954 Cagliari, Italy. 4955 CR BAK P, 1987, PHYS REV LETT, V59, P381 4956 BENHUR A, 1996, PHYS REV E, V53, P1317 4957 CHESSA A, UNPUB 4958 CHRISTENSEN K, 1993, PHYS REV E, V48, P3361 4959 DHAR D, 1990, PHYS REV LETT, V64, P1613 4960 DIAZGUILERA A, 1994, EUROPHYS LETT, V26, P177 4961 DICKMAN R, IN PRESS PHYS REV E 4962 DICKMAN R, 1996, NONEQUILIBRIUM STAT 4963 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 4964 LUBECK S, 1997, PHYS REV E A, V56, P5138 4965 LUBECK S, 1997, PHYS REV E, V55, P4095 4966 LUBECK S, 1997, PHYS REV E, V56, P1590 4967 MANNA SS, 1990, J STAT PHYS, V59, P509 4968 MANNA SS, 1990, J STAT PHYS, V61, P923 4969 PRIEZZHEV VB, 1994, J STAT PHYS, V74, P955 4970 SORNETTE D, 1995, J PHYS I, V5, P325 4971 VESPIGNANI A, IN PRESS PHYS REV E 4972 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 4973 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 4974 ZAPPERI S, 1995, PHYS REV LETT, V75, P4071 4975 ZHANG YC, 1989, PHYS REV LETT, V63, P470 4976 NR 21 4977 TC 10 4978 PU AMERICAN PHYSICAL SOC 4979 PI COLLEGE PK 4980 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 4981 SN 1063-651X 4982 J9 PHYS REV E 4983 JI Phys. Rev. E 4984 PD JUN 4985 PY 1998 4986 VL 57 4987 IS 6 4988 BP R6241 4989 EP R6244 4990 PG 4 4991 SC Physics, Fluids & Plasmas; Physics, Mathematical 4992 GA ZU947 4993 UT ISI:000074252400004 4994 ER 4995 4996 PT J 4997 AU Vespignani, A 4998 Zapperi, S 4999 TI How self-organized criticality works: A unified mean-field picture 5000 SO PHYSICAL REVIEW E 5001 LA English 5002 DT Article 5003 ID FOREST-FIRE MODEL; CRITICAL-BEHAVIOR; SANDPILE MODELS; 5004 BRANCHING-PROCESSES; NONEQUILIBRIUM SYSTEMS; PHASE-TRANSITIONS; ABELIAN 5005 SANDPILE; AVALANCHES; RENORMALIZATION; PERCOLATION 5006 AB We present a unified dynamical mean-field theory, based on the single 5007 site approximation to the master-equation, for stochastic 5008 self-organized critical models. In particular, we analyze in detail the 5009 properties of sandpile and forest-fire (FF) models. In analogy with 5010 other nonequilibrium critical phenomena, we identify an order parameter 5011 with the density of ''active'' sites, and control parameters with the 5012 driving rates. Depending on the values of the control parameters, the 5013 system is shown to reach a subcritical (absorbing) or supercritical 5014 (active) stationary state. Criticality is analyzed in terms of the 5015 singularities of the zero-field susceptibility. In the limit of 5016 vanishing control parameters, the stationary state displays scaling 5017 characteristics of self-organized criticality (SOC). We show that this 5018 limit corresponds to the breakdown of space-time locality in the 5019 dynamical rules of the models. We define a complete set of critical 5020 exponents, describing the scaling of order parameter, response 5021 functions, susceptibility and correlation length in the subcritical and 5022 supercritical states. In the subcritical state, the response of the 5023 system to small perturbations takes place in avalanches. We analyze 5024 their scaling behavior in relation with branching processes. In 5025 sandpile models, because of conservation laws, a critical exponents 5026 subset displays mean-field values (nu=1/2 and gamma=1) in any 5027 dimensions. We treat bull; and boundary dissipation and introduce a 5028 critical exponent relating dissipation and finite size effects. We 5029 present numerical simulations that confirm our results. In the case of 5030 the forest-fire model, our approach can distinguish between different 5031 regimes (SOC-FF and deterministic FF) studied in the literature, and 5032 determine the full spectrum of critical exponents. 5033 C1 Int Ctr Theoret Phys, I-34100 Trieste, Italy. 5034 Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. 5035 Boston Univ, Dept Phys, Boston, MA 02215 USA. 5036 RP Vespignani, A, Int Ctr Theoret Phys, POB 586, I-34100 Trieste, Italy. 5037 CR BAK P, 1987, PHYS REV LETT, V59, P381 5038 BAK P, 1988, PHYS REV A, V38, P364 5039 BAK P, 1990, PHYS LETT A, V147, P297 5040 BAK P, 1993, PHYS REV LETT, V71, P4083 5041 BENHUR A, 1996, PHYS REV E, V53, P1317 5042 BROKER HM, 1997, PHYS REV E A, V56, R4918 5043 BROKER HM, 1997, PHYS REV E, V56, P3944 5044 CALDARELLI G, UNPUB 5045 CHABANOL ML, 1997, PHYS REV E A, V56, R2343 5046 CHESSA A, UNPUB 5047 CHRISTENSEN K, 1993, PHYS REV E, V48, P3361 5048 CHRISTENSEN K, 1993, PHYS REV LETT, V71, P2737 5049 CLAR S, 1994, PHYS REV E A, V50, P1009 5050 CLAR S, 1996, J PHYS-CONDENS MAT, V8, P6803 5051 DHAR D, 1990, J PHYS A-MATH GEN, V23, P4333 5052 DHAR D, 1990, PHYS REV LETT, V64, P1613 5053 DIAZGUILERA A, 1992, PHYS REV A, V45, P8551 5054 DICKMAN R, 1986, PHYS REV A, V34, P4246 5055 DROSSEL B, 1993, PHYS REV LETT, V71, P3739 5056 DURIN G, 1995, FRACTALS, V3, P351 5057 ESSAM JW, 1972, PHASE TRANSITIONS CR, V2 5058 FIELD S, 1995, PHYS REV LETT, V74, P1206 5059 FLYVBJERG H, 1993, PHYS REV LETT, V71, P4087 5060 FRETTE V, 1996, NATURE, V379, P49 5061 GARCIAPELAYO R, 1994, PHYS REV E A, V49, P4903 5062 GIL L, 1996, PHYS REV LETT, V76, P3991 5063 GRASSBERGER P, 1979, ANN PHYS-NEW YORK, V122, P373 5064 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 5065 GRASSBERGER P, 1993, J PHYS A-MATH GEN, V26, P2081 5066 GRASSBERGER P, 1994, PHYS REV E, V49, P2436 5067 GRASSBERGER P, 1996, PHYSICA A, V224, P169 5068 GRINSTEIN G, 1990, PHYS REV LETT, V64, P1927 5069 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 5070 GUTENBERG B, 1956, ANN GEOFIS, V9, P1 5071 HARRIS TE, 1989, THEORY BRANCHING PRO 5072 HASTY J, 1997, J STAT PHYS, V86, P1179 5073 HENLEY CL, 1993, PHYS REV LETT, V71, P2741 5074 HWA T, 1989, PHYS REV LETT, V62, P1813 5075 IVASHKEVICH EV, 1996, PHYS REV LETT, V76, P3368 5076 JAEGER HM, 1989, PHYS REV LETT, V62, P40 5077 JANOWSKY SA, 1993, J PHYS A, V26, L973 5078 KADANOFF LP, 1989, PHYS REV A, V39, P6524 5079 KATORI M, 1996, PHYSICA A, V229, P461 5080 LAURITSEN KB, 1996, PHYS REV E, V54, P2483 5081 LILLY MP, 1993, PHYS REV LETT, V71, P4186 5082 LORETO V, 1995, PHYS REV LETT, V75, P465 5083 LUBECK S, 1997, PHYS REV E, V55, P4095 5084 LUBECK S, 1997, PHYS REV E, V56, P1590 5085 MANNA SS, 1990, J STAT PHYS, V59, P509 5086 MANNA SS, 1990, J STAT PHYS, V61, P923 5087 MANNA SS, 1991, J PHYS A, V24, L363 5088 MENDES JFF, 1994, J PHYS A-MATH GEN, V27, P3019 5089 MIDDLETON AA, 1995, PHYS REV LETT, V74, P742 5090 MUNOZ MA, 1996, PHYS REV LETT, V76, P451 5091 OLAMI Z, 1992, PHYS REV LETT, V68, P1244 5092 PACZUSKI M, 1996, PHYS REV E A, V53, P414 5093 PATZLAFF H, 1994, PHYS LETT A, V189, P187 5094 PETRI A, 1994, PHYS REV LETT, V73, P3423 5095 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 5096 PRIEZZHEV VB, 1994, J STAT PHYS, V74, P955 5097 SCHMITTMANN B, 1995, PHASE TRANSITIONS CR, V17 5098 SORNETTE D, 1992, J PHYS I, V2, P2065 5099 SORNETTE D, 1995, J PHYS I, V5, P325 5100 STELLA AL, 1995, PHYS REV E A, V52, P72 5101 SUKI B, 1994, NATURE, V368, P615 5102 TANG C, 1988, PHYS REV LETT, V60, P2347 5103 VERGELES M, 1997, PHYS REV E, V55, P1998 5104 VESPIGNANI A, UNPUB 5105 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 5106 VESPIGNANI A, 1996, PHYS REV LETT, V77, P4560 5107 VESPIGNANI A, 1997, J STAT PHYS, V88, P47 5108 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 5109 WILKINSON D, 1983, J PHYS A-MATH GEN, V16, P3365 5110 ZAPPERI S, 1995, PHYS REV LETT, V75, P4071 5111 ZHANG YC, 1989, PHYS REV LETT, V63, P470 5112 NR 75 5113 TC 111 5114 PU AMERICAN PHYSICAL SOC 5115 PI COLLEGE PK 5116 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 5117 SN 1063-651X 5118 J9 PHYS REV E 5119 JI Phys. Rev. E 5120 PD JUN 5121 PY 1998 5122 VL 57 5123 IS 6 5124 BP 6345 5125 EP 6362 5126 PG 18 5127 SC Physics, Fluids & Plasmas; Physics, Mathematical 5128 GA ZU947 5129 UT ISI:000074252400020 5130 ER 5131 5132 PT J 5133 AU Vespignani, A 5134 Zapperi, S 5135 Loreto, V 5136 TI Dynamically driven renormalization group applied to self-organized 5137 critical systems 5138 SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B 5139 LA English 5140 DT Article 5141 ID FOREST-FIRE MODEL; CRITICAL-BEHAVIOR; SANDPILE MODELS; SIMULATION; 5142 DIMENSIONS; STATES 5143 AB The Dynamically Driven Renormalization Group is a general framework 5144 developed to study the critical properties of nonequilibrium systems 5145 with stationary states. In particular this renormalization scheme 5146 allows the systematic analysis of several models showing self-organised 5147 criticality in terms of usual concepts of phase transitions and 5148 critical phenomena. 5149 C1 Leiden Univ, Inst Lorentz, NL-2300 RA Leiden, Netherlands. 5150 Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. 5151 Boston Univ, Dept Phys, Boston, MA 02215 USA. 5152 ENEA, Res Ctr, I-80055 Napoli, Italy. 5153 RP Vespignani, A, Leiden Univ, Inst Lorentz, POB 9506, NL-2300 RA Leiden, 5154 Netherlands. 5155 CR BAK P, 1987, PHYS REV LETT, V59, P381 5156 BAK P, 1988, PHYS REV A, V38, P364 5157 BAK P, 1990, PHYS LETT A, V147, P297 5158 BAK P, 1993, FRACTALS DISORDERED, V2 5159 BENHUR A, 1996, PHYS REV E, V54, P1426 5160 CHRISTENSEN K, 1993, PHYS REV LETT, V71, P2737 5161 CLAR S, 1994, PHYS REV E A, V50, P1009 5162 CRESWICK RJ, 1992, INTRO RENORMALIZATIO 5163 DOMB C, 1972, PHASE TRANSITION CRI, V1 5164 DOMB C, 1983, PHASE TRANSITION CRI, V7 5165 DROSSEL B, COMMUNICATION 5166 DROSSEL B, 1992, PHYS REV LETT, V69, P1629 5167 DROSSEL B, 1993, PHYS REV LETT, V71, P3739 5168 ERZAN A, 1995, REV MOD PHYS, V67, P545 5169 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 5170 GRASSBERGER P, 1991, J STAT PHYS, V63, P685 5171 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 5172 IVASHKEVICH EV, 1996, PHYS REV LETT, V76, P3368 5173 KATZ S, 1983, PHYS REV B, V28, P1655 5174 KATZ S, 1984, J STAT PHYS, V34, P497 5175 LORETO V, 1995, PHYS REV LETT, V75, P465 5176 MANDELBROT BB, 1983, FRACTAL GEOMETRY NAT 5177 MANNA SS, 1990, J STAT PHYS, V59, P509 5178 MANNA SS, 1991, PHYSICA A, V179, P249 5179 MOSSNER WK, 1992, PHYSICA A, V190, P205 5180 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 5181 STELLA AL, 1995, PHYS REV E A, V52, P72 5182 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 5183 VESPIGNANI A, 1997, J STAT PHYS, V88, P47 5184 VICSEK T, 1992, FRACTAL GROWTH PHENO 5185 ZHANG YC, 1989, PHYS REV LETT, V63, P470 5186 NR 31 5187 TC 0 5188 PU WORLD SCIENTIFIC PUBL CO PTE LTD 5189 PI SINGAPORE 5190 PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE 5191 SN 0217-9792 5192 J9 INT J MOD PHYS B 5193 JI Int. J. Mod. Phys. B 5194 PD MAY 30 5195 PY 1998 5196 VL 12 5197 IS 12-13 5198 BP 1407 5199 EP 1417 5200 PG 11 5201 SC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical 5202 GA ZT481 5203 UT ISI:000074092200015 5204 ER 5205 5206 PT J 5207 AU Dickman, R 5208 Vespignani, A 5209 Zapperi, S 5210 TI Self-organized criticality as an absorbing-state phase transition 5211 SO PHYSICAL REVIEW E 5212 LA English 5213 DT Article 5214 ID REGGEON FIELD-THEORY; CRITICAL-BEHAVIOR; CELLULAR-AUTOMATA; 2 5215 DIMENSIONS; AVALANCHES; SYSTEMS; DYNAMICS; LATTICE; MODELS; NOISE 5216 AB We explore the connection between self-organized criticality and phase 5217 transitions in models with absorbing states. sandpile models are found 5218 to exhibit criticality only when a pair of relevant parameters - 5219 dissipation epsilon and driving field h - are set to their critical 5220 values. The critical values of epsilon and h are both equal to zero. 5221 The first result is due to the absence of saturation (no bound on 5222 energy) in the sandpile model, while the second result is common to 5223 other absorbing-state transitions. The original definition of the 5224 sandpile model places it at the point (epsilon = 0,h = 0(+)): it is 5225 critical by definition. We argue power-law avalanche distributions are 5226 a general feature of models with infinitely many absorbing 5227 configurations, when they are subject to slow driving at the critical 5228 point. Our assertions are supported by simulations of the sandpile at 5229 epsilon=h=0 and fixed energy density zeta (no drive, periodic 5230 boundaries), and of the slowly driven pair contact process. We 5231 formulate a held theory for the sandpile model, in which the order 5232 parameter is coupled to a conserved energy density, which plays the 5233 role of an effective creation rate. 5234 C1 CUNY Herbert H Lehman Coll, Dept Phys & Astron, Bronx, NY 10468 USA. 5235 Int Ctr Theoret Phys, I-34100 Trieste, Italy. 5236 Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. 5237 Boston Univ, Dept Phys, Boston, MA 02215 USA. 5238 RP Dickman, R, Univ Fed Santa Catarina, Dept Fis, Campus Univ, BR-88040900 5239 Florianopolis, SC, Brazil. 5240 CR BAK P, 1987, PHYS REV LETT, V59, P381 5241 BAK P, 1988, PHYS REV A, V38, P364 5242 BAK P, 1996, NATURE WORKS 5243 CARDY JL, 1980, J PHYS A, V13, L423 5244 CLAR S, 1996, J PHYS-CONDENS MAT, V8, P6803 5245 DIAZGUILERA A, 1992, PHYS REV A, V45, P8551 5246 DIAZGUILERA A, 1994, EUROPHYS LETT, V26, P177 5247 DICKMAN R, UNPUB 5248 DICKMAN R, 1996, NONEQUILIBRIUM STAT 5249 DICKMAN R, 1996, PHYS REV E, V53, P2223 5250 DURIN G, 1995, FRACTALS, V3, P351 5251 FIELD S, 1995, PHYS REV LETT, V74, P1206 5252 GRASSBERGER P, 1979, ANN PHYS-NEW YORK, V122, P373 5253 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 5254 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 5255 GUTENBERG B, 1956, ANN GEOFIS, V9, P1 5256 HARRIS TE, 1974, ANN PROBAB, V2, P969 5257 JANSSEN HK, 1981, Z PHYS B CON MAT, V42, P151 5258 JENSEN I, 1993, PHYS REV E, V48, P1710 5259 JENSEN I, 1993, PHYS REV LETT, V70, P1465 5260 KADANOFF LP, 1989, PHYS REV A, V39, P6524 5261 KATORI M, 1996, PHYSICA A, V229, P461 5262 KINZEL W, 1985, Z PHYS B CON MAT, V58, P229 5263 LILLY MP, 1993, PHYS REV LETT, V71, P4186 5264 LUBECK S, 1997, CONDMAT9708055 5265 LUBECK S, 1997, PHYS REV E, V55, P4095 5266 LUBECK S, 1997, PHYS REV E, V56, P1590 5267 MANNA SS, 1990, J STAT PHYS, V59, P509 5268 MANNA SS, 1990, J STAT PHYS, V61, P923 5269 MANNA SS, 1991, J PHYS A, V24, L363 5270 MANNA SS, 1991, PHYSICA A, V179, P249 5271 MARRO J, 1997, NONEQUILIBRIUM PHASE 5272 MENDES JFF, 1994, J PHYS A-MATH GEN, V27, P3019 5273 MUNOZ MA, IN PRESS J STAT PHYS 5274 MUNOZ MA, 1996, PHYS REV LETT, V76, P451 5275 MUNOZ MA, 1997, PHYSICA D, V103, P485 5276 PACZUSKI M, 1996, PHYS REV E A, V53, P414 5277 PELITI L, 1985, J PHYS-PARIS, V46, P1469 5278 PETRI A, 1994, PHYS REV LETT, V73, P3423 5279 PRIEZZHEV VB, 1994, J STAT PHYS, V74, P955 5280 SAHIMI M, 1993, REV MOD PHYS, V65, P1393 5281 SORNETTE D, 1995, J PHYS I, V5, P325 5282 SPASOJEVIC D, 1996, PHYS REV E, V54, P2531 5283 SUKI B, 1994, NATURE, V368, P615 5284 VESPIGNANI A, 1996, PHYS REV LETT, V77, P4560 5285 VESPIGNANI A, 1997, J STAT PHYS, V88, P47 5286 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 5287 ZAPPERI S, UNPUB 5288 ZAPPERI S, 1997, NATURE, V388, P658 5289 NR 49 5290 TC 78 5291 PU AMERICAN PHYSICAL SOC 5292 PI COLLEGE PK 5293 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 5294 SN 1063-651X 5295 J9 PHYS REV E 5296 JI Phys. Rev. E 5297 PD MAY 5298 PY 1998 5299 VL 57 5300 IS 5 5301 PN Part A 5302 BP 5095 5303 EP 5105 5304 PG 11 5305 SC Physics, Fluids & Plasmas; Physics, Mathematical 5306 GA ZP582 5307 UT ISI:000073767900034 5308 ER 5309 5310 PT J 5311 AU Chessa, A 5312 Marinari, E 5313 Vespignani, A 5314 TI Energy constrained sandpile models 5315 SO PHYSICAL REVIEW LETTERS 5316 LA English 5317 DT Article 5318 ID SELF-ORGANIZED CRITICALITY; NOISE 5319 AB We study two driven dynamical systems with conserved energy. The two 5320 automata contain the basic dynamical rules of the Bak, Tang, and 5321 Wiesenfeld sandpile model. In addition a global constraint on the 5322 energy contained in the lattice is imposed. In the limit of an 5323 infinitely slow driving of the system, the conserved energy E becomes 5324 the only parameter governing the dynamical behavior of the system. Both 5325 models show scale-fret behavior at a critical value E-c of the fixed 5326 energy. The scaling with respect to the relevant scaling field points 5327 out that the developing of critical correlations is in a different 5328 universality class than self-organized critical sandpiles. Despite this 5329 difference, the activity (avalanche) probability distributions appear 5330 to coincide with the one of the standard self-organized critical 5331 sandpile. 5332 C1 Univ Cagliari, Dipartimento Fis, I-09124 Cagliari, Italy. 5333 INFM, Cagliari, Italy. 5334 Ist Nazl Fis Nucl, Cagliari, Italy. 5335 Int Ctr Theoret Phys, I-34100 Trieste, Italy. 5336 RP Chessa, A, Univ Cagliari, Dipartimento Fis, Via Osped 72, I-09124 5337 Cagliari, Italy. 5338 CR BAK P, 1987, PHYS REV LETT, V59, P381 5339 BAK P, 1988, PHYS REV A, V38, P364 5340 BENHUR A, 1996, PHYS REV E, V53, P1317 5341 CHESSA A, IN PRESS 5342 CHESSA A, 1998, CONDMAT9802123 5343 DICKMAN R, IN PRESS 5344 DICKMAN R, 1996, NONEQUILIBRIUM STAT 5345 DURIN G, 1995, FRACTALS, V3, P351 5346 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 5347 GRINSTEIN G, 1995, SCALE INVARIANCE I B, V344 5348 GUTENBERG B, 1956, ANN GEOFIS, V9, P1 5349 LUBECK S, 1997, PHYS REV E, V55, P4095 5350 LUBECK S, 1997, PHYS REV E, V56, P1590 5351 MANNA SS, 1990, J STAT PHYS, V59, P509 5352 MANNA SS, 1991, PHYSICA A, V179, P249 5353 PETRI A, 1994, PHYS REV LETT, V73, P3423 5354 SORNETTE D, 1995, J PHYS I, V5, P325 5355 SPASOJEVIC D, 1996, PHYS REV E, V54, P2531 5356 VESPIGNANI A, 1997, PHYS REV LETT, V78, P4793 5357 ZAPPERI S, 1997, NATURE, V388, P658 5358 NR 20 5359 TC 18 5360 PU AMERICAN PHYSICAL SOC 5361 PI COLLEGE PK 5362 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 5363 SN 0031-9007 5364 J9 PHYS REV LETT 5365 JI Phys. Rev. Lett. 5366 PD MAY 11 5367 PY 1998 5368 VL 80 5369 IS 19 5370 BP 4217 5371 EP 4220 5372 PG 4 5373 SC Physics, Multidisciplinary 5374 GA ZM538 5375 UT ISI:000073550200027 5376 ER 5377 5378 PT J 5379 AU Cafiero, R 5380 Vespignani, A 5381 Zapperi, S 5382 Pietronero, L 5383 TI Universality and scale invariant dynamics in laplacian fractal growth 5384 SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B 5385 LA English 5386 DT Article 5387 ID DIFFUSION-LIMITED AGGREGATION; RENORMALIZATION-GROUP APPROACH; INVASION 5388 PERCOLATION; DIELECTRIC-BREAKDOWN; BRANCHED GROWTH; CLUSTERS; MODELS; 5389 MEDIA 5390 AB The individuation of the scale invariant dynamics in Laplacian fractal 5391 growth processes, like diffusion-limited aggregation (DLA), is an 5392 important problem whose solution would clarify some crucial issues 5393 concerning the origin of fractal properties and the identification of 5394 universality classes for such models. Here, we develop a real space 5395 renormalization group scheme to study the dynamic evolution of DLA in a 5396 restricted space of relevant parameters. In particular, we investigate 5397 the effect of a sticking probability P-s and an effective noise 5398 reduction parameter S. The renormalization equations flow towards an 5399 attractive fixed point corresponding to the scale invariant DLA 5400 dynamics (P-s* = 1, S* similar or equal to 2.0). The existence of a 5401 non-trivial fixed point value for S, shows that noise is spontaneously 5402 generated by the DLA growth process, and that screening, which is at 5403 the origin of fractal properties, persists at all scales. 5404 C1 Max Planck Inst Phys Complex Syst, D-01187 Dresden, Germany. 5405 Int Ctr Theoret Phys, I-34100 Trieste, Italy. 5406 Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. 5407 Boston Univ, Dept Phys, Boston, MA 02215 USA. 5408 Univ Rome La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. 5409 Univ Rome La Sapienza, Unita INFM, I-00185 Rome, Italy. 5410 RP Cafiero, R, Max Planck Inst Phys Complex Syst, Thnitzer Str 38, D-01187 5411 Dresden, Germany. 5412 CR AMITRANO C, 1993, FRACTALS, V1, P840 5413 BARKER PW, 1990, PHYS REV A, V42, P6289 5414 CAFIERO R, 1993, PHYS REV LETT, V70, P3939 5415 CAFIERO R, 1996, PHYS REV E, V54, P1406 5416 CAFIERO R, 1997, PHYS REV LETT, V79, P1503 5417 DEANGELIS R, 1991, EUROPHYS LETT, V16, P417 5418 DEARCANGELIS L, 1989, PHYS REV B, V40, P877 5419 ECKMANN JP, 1989, PHYS REV A, V39, P3185 5420 EDEN M, 1961, 4 BERK S MATH STAT P, P223 5421 ERZAN A, 1995, REV MOD PHYS, V67, P861 5422 EVERTSZ C, 1990, PHYS REV A, V41, P1830 5423 FAMILY F, 1986, J PHYS A, V19, L733 5424 HALSEY TC, 1992, PHYS REV A, V46, P7793 5425 HALSEY TC, 1994, PHYS REV LETT, V72, P1228 5426 HASTINGS MB, CONDMAT9607007 5427 HASTINGS MB, CONDMAT9607021 5428 JULLIEN R, 1984, J PHYS A, V17, L639 5429 KERTESZ J, 1986, J PHYS A, V19, L257 5430 MANDELBROT BB, 1995, EUROPHYS LETT, V32, P199 5431 MARSILI M, 1994, J STAT PHYS, V77, P733 5432 MEAKIN P, 1983, PHYS REV A, V27, P1495 5433 MEAKIN P, 1983, PHYS REV LETT, V51, P1119 5434 MEAKIN P, 1988, PHASE TRANSITIONS CR, V12, P335 5435 MOUKARZEL C, 1992, PHYSICA A, V188, P469 5436 NAGATANI T, 1987, J PHYS A, V20, L381 5437 NAGATANI T, 1987, PHYS REV A, V36, P5812 5438 NEIMEYER L, 1984, PHYS REV LETT, V52, P1033 5439 NITTMANN J, 1986, NATURE, V321, P663 5440 PIETRONERO L, 1990, PHYSICA A, V119, P249 5441 VESPIGNANI A, 1993, FRACTALS, V1, P1002 5442 VICSEK T, 1992, FRACTAL GROWTH PHENO 5443 WANG XR, 1989, J PHYS A, V22, L507 5444 WANG XR, 1989, PHYS REV A, V39, P5974 5445 WILKINSON D, 1983, J PHYS A-MATH GEN, V16, P3365 5446 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 5447 NR 35 5448 TC 0 5449 PU WORLD SCIENTIFIC PUBL CO PTE LTD 5450 PI SINGAPORE 5451 PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE 5452 SN 0217-9792 5453 J9 INT J MOD PHYS B 5454 JI Int. J. Mod. Phys. B 5455 PD DEC 10 5456 PY 1997 5457 VL 11 5458 IS 30 5459 BP 3595 5460 EP 3619 5461 PG 25 5462 SC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical 5463 GA YP694 5464 UT ISI:000071304600006 5465 ER 5466 5467 PT J 5468 AU Vespignani, A 5469 Zapperi, S 5470 Loreto, V 5471 TI Dynamically driven renormalization group 5472 SO JOURNAL OF STATISTICAL PHYSICS 5473 LA English 5474 DT Article 5475 DE renormalization group; nonequilibrium steady states; driven dynamical 5476 systems; self-organized criticality 5477 ID FOREST-FIRE MODEL; SELF-ORGANIZED CRITICALITY; MEAN-FIELD THEORY; 5478 CRITICAL-BEHAVIOR; SANDPILE MODELS; LATTICE GAS; DIMENSIONS; SYSTEMS; 5479 STATES; SCHEME 5480 AB We present a detailed discussion of a novel dynamical renormalization 5481 group scheme: the dynamically driven renormalization group (DDRG). This 5482 is a general renormalization method developed for dynamical systems 5483 with nonequilibrium critical steady state. The method is based on a 5484 real-space renormalization scheme driven by a dynamical steady-state 5485 condition which acts as a feedback on the transformation equations. 5486 This approach has been applied to open nonlinear systems such as 5487 self-organized critical phenomena, and it allows the analytical 5488 evaluation of scaling dimensions and critical exponents. Equilibrium 5489 models at the critical point can also be considered. The explicit 5490 application to some models and the corresponding results are discussed. 5491 C1 BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215. 5492 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. 5493 UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY. 5494 RP Vespignani, A, LEIDEN UNIV,INST LORENTZ,POB 9506,NL-2300 RA 5495 LEIDEN,NETHERLANDS. 5496 CR ACHIAM Y, 1978, PHYS REV LETT, V41, P128 5497 AMIT DJ, 1984, FIELD THEORY RENORMA 5498 BAK P, 1987, PHYS REV LETT, V59, P381 5499 BAK P, 1988, PHYS REV A, V38, P364 5500 BAK P, 1989, NETURE, V342, P7800 5501 BAK P, 1990, PHYS LETT A, V147, P297 5502 BAK P, 1993, FRACTALS DISORDERED, V2 5503 BENHUR A, 1996, PHYS REV E, V54, P1426 5504 BURKHARDT TW, 1982, REAL SPACE RENORMALI 5505 CHRISTENSEN K, 1993, PHYS REV LETT, V71, P2737 5506 CLAR S, 1994, PHYS REV E A, V50, P1009 5507 CRESWICK RJ, 1992, INTRO RENORMALIZATIO 5508 DHAR D, 1989, PHYS REV LETT, V63, P1659 5509 DHAR D, 1990, PHYS REV LETT, V64, P1613 5510 DICKMAN R, 1988, PHYS REV A, V38, P2588 5511 DOMB C, 1972, PHASE TRANSITION CRI, V1 5512 DOMB C, 1983, PHASE TRANSITION CRI, V7 5513 DROSSEL B, 1992, PHYS REV LETT, V69, P1629 5514 DROSSEL B, 1993, PHYS REV LETT, V71, P3739 5515 ERZAN A, 1995, REV MOD PHYS, V67, P545 5516 GLAUBER RJ, 1963, J MATH PHYS, V4, P294 5517 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 5518 GRASSBERGER P, 1991, J STAT PHYS, V63, P685 5519 GRASSBERGER P, 1993, J PHYS A-MATH GEN, V26, P2081 5520 GRINSTEIN G, 1995, SCALE INVARIANCE I B, V344 5521 HENLEY CL, 1993, PHYS REV LETT, V71, P2741 5522 HUANG K, 1987, STATISTICAL MECHANIC 5523 IVASHKEVICH EV, 1996, PHYS REV LETT, V76, P3368 5524 KADANOFF LP, 1966, PHYSICS, V2, P263 5525 KADANOFF LP, 1976, ANN PHYS-NEW YORK, V100, P359 5526 KADANOFF LP, 1990, PHYSICA A, V163, P1 5527 KADANOFF LP, 1991, PHYS TODAY, V44, P9 5528 KATZ S, 1983, PHYS REV B, V28, P1655 5529 KATZ S, 1984, J STAT PHYS, V34, P497 5530 KEIZER J, 1987, STAT THERMODYNAMICS 5531 LORETO V, 1995, PHYS REV LETT, V75, P465 5532 LORETO V, 1996, J PHYS A-MATH GEN, V29, P2981 5533 MA SK, 1976, MODERN THEORY CRITIC 5534 MAJUMDAR SN, 1992, PHYSICA A, V185, P129 5535 MANDELBROT BB, 1983, FRACTAL GEOMETRY NAT 5536 MANNA SS, 1991, PHYSICA A, V179, P249 5537 MAZENKO GF, 1982, REAL SPACE RENORMALI, P87 5538 MIGDAL AA, 1975, SOV PHYS JETP, V42, P413 5539 MOSSNER WK, 1992, PHYSICA A, V190, P205 5540 NIEMEIJER T, 1976, FRACTAL GEOMETRY NAT, V6 5541 PARISI G, 1988, STAT FIELD THEORY 5542 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 5543 PRENTIS JJ, 1995, J PHYS A, V528, P5469 5544 SCHMITTMANN B, 1995, PHASE TRANSITION CRI, V17 5545 STELLA AL, 1995, PHYS REV E A, V52, P72 5546 SUZUKI M, 1974, PROG THEOR PHYS, V51, P1257 5547 SUZUKI M, 1979, DYNAMICAL CRITICAL P, V104 5548 SUZUKI M, 1979, PROG THEOR PHYS, V61, P864 5549 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 5550 VICSEK T, 1992, FRACTAL GROWTH PHENO 5551 YEOMANS JM, 1992, STAT MECH PHASE TRAN 5552 ZHANG YC, 1989, PHYS REV LETT, V63, P470 5553 NR 57 5554 TC 10 5555 PU PLENUM PUBL CORP 5556 PI NEW YORK 5557 PA 233 SPRING ST, NEW YORK, NY 10013 5558 SN 0022-4715 5559 J9 J STATIST PHYS 5560 JI J. Stat. Phys. 5561 PD JUL 5562 PY 1997 5563 VL 88 5564 IS 1-2 5565 BP 47 5566 EP 79 5567 PG 33 5568 SC Physics, Mathematical 5569 GA XT833 5570 UT ISI:A1997XT83300003 5571 ER 5572 5573 PT J 5574 AU Zapperi, S 5575 Vespignani, A 5576 Stanley, HE 5577 TI Plasticity and avalanche behaviour in microfracturing phenomena 5578 SO NATURE 5579 LA English 5580 DT Article 5581 ID SELF-ORGANIZED CRITICALITY; ACOUSTIC-EMISSION; FUSE NETWORKS; POWER 5582 LAWS; DYNAMICS 5583 AB Inhomogeneous materials, such as plaster or concrete, subjected to an 5584 external elastic stress display sudden movements owing to the formation 5585 and propagation of microfractures. Studies of acoustic emission from 5586 these systems reveal power-law behaviour(1). Similar behaviour in 5587 damage propagation has also been seen in acoustic emission resulting 5588 from volcanic activity(2) and hydrogen precipitation in niobium(3). It 5589 has been suggested that the underlying fracture dynamics in these 5590 systems might display self-organized criticality(4), implying that 5591 long-ranged correlations between fracture events lead to a scale-free 5592 cascade of 'avalanches'. A hierarchy of avalanche events is also 5593 observed in a wide range of other systems, such as the dynamics of 5594 random magnets(5) and high-temperature superconductors(6) in magnetic 5595 fields, lung inflation(7) and seismic behaviour characterized by the 5596 Gutenberg-Richter law(8). The applicability of self-organized 5597 criticality to microfracturing has been questioned(9,10), however, as 5598 power laws alone are not unequivocal evidence for it. Here we present a 5599 scalar model of microfracturing which generates power-law behaviour in 5600 properties related to acoustic emission, and a scale-free hierarchy of 5601 avalanches characteristic of self-organized criticality. The geometric 5602 structure of the fracture surfaces agrees with that seen 5603 experimentally. We find that the critical steady state exhibits plastic 5604 macroscopic behaviour, which is commonly observed in real materials. 5605 C1 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. 5606 LEIDEN UNIV,INST LORENTZ,NL-2300 RA LEIDEN,NETHERLANDS. 5607 RP Zapperi, S, BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215. 5608 CR BAK P, 1987, PHYS REV LETT, V59, P381 5609 CALDARELLI G, 1996, PHYS REV LETT, V77, P2503 5610 CANNELLI G, 1993, PHYS REV LETT, V70, P3923 5611 CANNELLI G, 1994, PHYS REV LETT, V72, P2307 5612 CHEN WF, 1982, PLASTICITY REINFORCE 5613 COTE PJ, 1991, PHYS REV LETT, V67, P1334 5614 DEARCANGELIS L, 1985, J PHYS LETT, V46, L585 5615 DEARCANGELIS L, 1989, PHYS REV B, V39, P2678 5616 DIODATI P, 1991, PHYS REV LETT, V67, P2239 5617 FIELD S, 1995, PHYS REV LETT, V74, P1206 5618 GUTENBERG B, 1944, B SEISMOL SOC AM, V34, P185 5619 HERRMANN HJ, 1990, STAT MODELS FRACTURE 5620 HERRMANN HJ, 1991, EUROPHYS LETT, V10, P514 5621 LANDAU LD, 1960, THEORY ELASTICITY 5622 MILTENBERGER P, 1993, PHYS REV LETT, V71, P3604 5623 OKUZONO T, 1995, PHYS REV E, V51, P1246 5624 OMORI F, 1894, J COLL SCI IMP U TOK, V7, P111 5625 PETRI A, 1994, PHYS REV LETT, V73, P3423 5626 PRESS WH, 1991, COMPUT PHYS, V5, P154 5627 SAHIMI M, 1996, PHYS REV LETT, V77, P3689 5628 SORNETTE D, 1992, PHYS REV LETT, V68, P612 5629 SORNETTE D, 1994, J PHYS I, V4, P209 5630 SORNETTE D, 1994, PHYS REV LETT, V72, P2306 5631 STROEVEN P, 1990, ENG FRACT MECH, V35, P775 5632 STROEVEN P, 1993, INTERFACES CEMENTOUS, P187 5633 SUKI B, 1994, NATURE, V368, P615 5634 TILLEMANS HJ, 1995, PHYSICA A, V217, P261 5635 TZSCHICHHOLZ F, 1995, PHYS REV E, V51, P1961 5636 WILSHIRE B, 1983, ENG APPROACHES HIGH 5637 NR 29 5638 TC 64 5639 PU MACMILLAN MAGAZINES LTD 5640 PI LONDON 5641 PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW 5642 SN 0028-0836 5643 J9 NATURE 5644 JI Nature 5645 PD AUG 14 5646 PY 1997 5647 VL 388 5648 IS 6643 5649 BP 658 5650 EP 660 5651 PG 3 5652 SC Multidisciplinary Sciences 5653 GA XQ863 5654 UT ISI:A1997XQ86300044 5655 ER 5656 5657 PT J 5658 AU Vespignani, A 5659 Zapperi, S 5660 TI Order parameter and scaling fields in self-organized criticality 5661 SO PHYSICAL REVIEW LETTERS 5662 LA English 5663 DT Article 5664 ID CRITICAL EXPONENTS; CRITICAL-BEHAVIOR; SANDPILE MODELS; LATTICE; 5665 SIMULATION; DIMENSIONS; AUTOMATON 5666 AB We present a unified dynamical mean-held theory for stochastic 5667 self-organized critical models. We, use a single site approximation, 5668 and we include the details of different models by using effective 5669 parameters and constraints. We identify the order parameter and the 5670 relevant scaling fields in order to describe the critical behavior in 5671 terms of the usual concepts of nonequilibrium lattice models with 5672 steady states. We point out the inconsistencies of previous mean-field 5673 approaches, which lead to different predictions. Numerical simulations 5674 confirm the validity of our results beyond mean-field theory. 5675 C1 BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215. 5676 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. 5677 RP Vespignani, A, LEIDEN UNIV,INST LORENTZ,POB 9506,NL-2300 RA 5678 LEIDEN,NETHERLANDS. 5679 CR BAK P, 1987, PHYS REV LETT, V59, P381 5680 BAK P, 1988, PHYS REV A, V38, P364 5681 CALDARELLI G, UNPUB 5682 CALDARELLI G, 1996, EUROPHYS LETT, V35, P481 5683 CHRISTENSEN K, 1993, PHYS REV E, V48, P3361 5684 CHRISTENSEN K, 1993, PHYS REV LETT, V71, P2737 5685 CLAR S, 1996, J PHYS-CONDENS MAT, V8, P6803 5686 DHAR D, 1990, PHYS REV LETT, V64, P1613 5687 DICKMAN R, 1986, PHYS REV A, V34, P4246 5688 DICKMAN R, 1988, PHYS REV A, V38, P2588 5689 DICKMAN R, 1989, J STAT PHYS, V55, P997 5690 GRASSBERGER P, 1979, ANN PHYS-NEW YORK, V122, P373 5691 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 5692 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 5693 LAURITSEN KB, 1996, PHYS REV E, V54, P2483 5694 MANDELBROT BB, 1983, FRACTAL GEOMETRY NAT 5695 MANNA SS, 1990, J STAT PHYS, V59, P509 5696 MANNA SS, 1990, J STAT PHYS, V61, P923 5697 MANNA SS, 1991, J PHYS A, V24, L363 5698 MANNA SS, 1991, PHYSICA A, V179, P249 5699 MENDES JFF, 1994, J PHYS A-MATH GEN, V27, P3019 5700 MUNOZ MA, 1996, PHYS REV LETT, V76, P451 5701 PIETRONERO L, 1991, PHYSICA A, V173, P129 5702 SCHMITTMANN B, 1995, PHASE TRANSITION CRI, V17 5703 SORNETTE D, 1995, J PHYS I, V5, P325 5704 STELLA AL, 1995, PHYS REV E A, V52, P72 5705 TANG C, 1988, J STAT PHYS, V51, P797 5706 TANG C, 1988, PHYS REV LETT, V60, P2347 5707 TOME T, 1994, PHYSICA A, V212, P99 5708 VERGELES M, 1997, PHYS REV E, V55, P1998 5709 VESPIGNANI A, UNPUB 5710 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 5711 VESPIGNANI A, 1996, PHYS REV LETT, V77, P4560 5712 ZHANG YC, 1989, PHYS REV LETT, V63, P470 5713 NR 34 5714 TC 61 5715 PU AMERICAN PHYSICAL SOC 5716 PI COLLEGE PK 5717 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 5718 SN 0031-9007 5719 J9 PHYS REV LETT 5720 JI Phys. Rev. Lett. 5721 PD JUN 23 5722 PY 1997 5723 VL 78 5724 IS 25 5725 BP 4793 5726 EP 4796 5727 PG 4 5728 SC Physics, Multidisciplinary 5729 GA XJ269 5730 UT ISI:A1997XJ26900031 5731 ER 5732 5733 PT J 5734 AU Zapperi, S 5735 Ray, P 5736 Stanley, HE 5737 Vespignani, A 5738 TI First-order transition in the breakdown of disordered media 5739 SO PHYSICAL REVIEW LETTERS 5740 LA English 5741 DT Article 5742 ID SELF-ORGANIZED CRITICALITY; ACOUSTIC-EMISSION; ELECTRICAL BREAKDOWN; 5743 NUCLEATION; EARTHQUAKES; FRACTURE; DYNAMICS; GROWTH; SOLIDS; MODEL 5744 AB We study the approach to global breakdown in disordered media driven by 5745 increasing external forces. We first analyze the problem by mean-field 5746 theory, showing that the failure process can be described as a 5747 first-order phase transition, similarly to the case of thermally 5748 activated fracture in homogeneous media. Then we quantitatively confirm 5749 the predictions of the mean-field theory using numerical simulations of 5750 discrete models. Widely distributed avalanches and the corresponding 5751 mean-field scaling are explained by the long-range nature of elastic 5752 interactions. We discuss the analogy of our results to driven 5753 disordered first-order transitions and spinodal nucleation in magnetic 5754 systems. 5755 C1 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. 5756 INST MATH SCI,MADRAS 600113,TAMIL NADU,INDIA. 5757 LEIDEN UNIV,INST LORENTZ,NL-2300 RA LEIDEN,NETHERLANDS. 5758 RP Zapperi, S, BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215. 5759 CR ACHARYYA M, 1996, PHYS REV E A, V53, P140 5760 ACHARYYA M, 1996, PHYSICA A, V224, P287 5761 ANIFRANI JC, 1995, J PHYS I, V5, P631 5762 BAK P, 1987, PHYS REV LETT, V59, P381 5763 BARDHAN KK, 1994, NONLINEARITY BREAKDO 5764 BUCHEL A, CONDMAT9610008 5765 BUCHEL A, 1996, PHYS REV LETT, V77, P1520 5766 CALDARELLI G, 1996, PHYS REV LETT, V77, P2503 5767 CANNELLI G, 1993, PHYS REV LETT, V70, P3923 5768 DAHMEN K, 1996, PHYS REV B, V53, P14872 5769 DANIELS HE, 1945, PROC R SOC LON SER-A, V183, P405 5770 DEARCANGELIS L, 1985, J PHYS LETT, V46, L585 5771 DEARCANGELIS L, 1989, PHYS REV B, V39, P2678 5772 DIODATI P, 1991, PHYS REV LETT, V67, P2239 5773 DUXBURY PM, 1986, PHYS REV LETT, V57, P1052 5774 GOLUBOVIC L, 1991, PHYS REV A, V43, P5223 5775 GOLUBOVIC L, 1995, PHYS REV E A, V51, P2799 5776 GRIFFITH AA, 1920, PHILOS T R SOC A, V221, P163 5777 GUNTON JD, 1983, PHASE TRANSITIONS CR, V8 5778 HEERMANN DW, 1982, PHYS REV LETT, V49, P1262 5779 HEMMER PC, 1992, J APPL MECH-T ASME, V59, P909 5780 HERRMANN HJ, 1990, STAT MODELS FRACTURE 5781 KAHNG B, 1988, PHYS REV B, V37, P7625 5782 KIRKPATRICK S, 1973, REV MOD PHYS, V45, P574 5783 MONETTE L, 1994, INT J MOD PHYS B, V8, P1417 5784 OLAMI Z, 1992, PHYS REV LETT, V68, P1244 5785 PETRI A, 1994, PHYS REV LETT, V73, P3423 5786 PHOENIX SL, 1973, ADV APPL PROBAB, V5, P200 5787 RAY P, 1996, PHYSICA A, V229, P26 5788 RAY TS, 1990, J STAT PHYS, V61, P891 5789 RUNDLE JB, 1989, PHYS REV LETT, V63, P171 5790 RUNDLE JB, 1996, PHYS REV LETT, V76, P4285 5791 SAHIMI M, 1996, PHYS REV LETT, V77, P3689 5792 SELINGER RLB, 1991, J CHEM PHYS, V95, P9128 5793 SELINGER RLB, 1991, PHYS REV A, V43, P4396 5794 SETHNA JP, 1993, PHYS REV LETT, V70, P3347 5795 SORNETTE D, 1989, J PHYS A, V22, L243 5796 SORNETTE D, 1992, J PHYS I, V2, P2089 5797 SORNETTE D, 1994, J PHYS I, V4, P209 5798 STRAUVEN H, IN PRESS 5799 TILLEMANS HJ, 1995, PHYSICA A, V217, P261 5800 TZSCHICHHOLZ F, 1995, PHYS REV E, V51, P1961 5801 UNGER C, 1984, PHYS REV B, V29, P2698 5802 UNGER C, 1985, PHYS REV B, V31, P6127 5803 VESPIGNANI A, 1996, PHYS REV LETT, V77, P4560 5804 ZAPPERI S, IN PRESS 5805 ZAPPERI S, 1996, MATER RES SOC SYMP P, V409, P355 5806 NR 47 5807 TC 98 5808 PU AMERICAN PHYSICAL SOC 5809 PI COLLEGE PK 5810 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 5811 SN 0031-9007 5812 J9 PHYS REV LETT 5813 JI Phys. Rev. Lett. 5814 PD FEB 24 5815 PY 1997 5816 VL 78 5817 IS 8 5818 BP 1408 5819 EP 1411 5820 PG 4 5821 SC Physics, Multidisciplinary 5822 GA WK157 5823 UT ISI:A1997WK15700003 5824 ER 5825 5826 PT J 5827 AU Loreto, V 5828 Pietronero, L 5829 Vespignani, A 5830 Zapperi, S 5831 TI Renormalization group approach to the critical behavior of the 5832 forest-fire model - Reply 5833 SO PHYSICAL REVIEW LETTERS 5834 LA English 5835 DT Article 5836 C1 LEIDEN UNIV,INST LORENTZ,NL-2300 RA LEIDEN,NETHERLANDS. 5837 BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215. 5838 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. 5839 RP Loreto, V, UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,P A MORO 2,I-00185 5840 ROME,ITALY. 5841 CR BURKHARDT TW, 1982, REAL SPACE RENORMALI 5842 DROSSEL B, 1996, PHYS REV LETT, V76, P936 5843 DROSSEL B, 1997, PHYS REV LETT, V78, P1392 5844 LORETO V, 1995, PHYS REV LETT, V75, P465 5845 VESPIGNANI A, IN PRESS J STAT PHYS 5846 VESPIGNANI A, 1996, PHYS REV LETT, V77, P4560 5847 NR 6 5848 TC 0 5849 PU AMERICAN PHYSICAL SOC 5850 PI COLLEGE PK 5851 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 5852 SN 0031-9007 5853 J9 PHYS REV LETT 5854 JI Phys. Rev. Lett. 5855 PD FEB 17 5856 PY 1997 5857 VL 78 5858 IS 7 5859 BP 1393 5860 EP 1393 5861 PG 1 5862 SC Physics, Multidisciplinary 5863 GA WH917 5864 UT ISI:A1997WH91700051 5865 ER 5866 5867 PT J 5868 AU Piccioni, M 5869 Cafiero, R 5870 Vespignani, A 5871 TI Monte Carlo fixed scale transformation for nonlocal fractal growth 5872 models 5873 SO PHYSICAL REVIEW E 5874 LA English 5875 DT Article 5876 ID DIFFUSION-LIMITED AGGREGATION; DIELECTRIC-BREAKDOWN MODEL; PERCOLATION 5877 AB The fixed scale transformation (FST) is a theoretical framework 5878 developed for the evaluation of scaling dimensions in a vast class of 5879 complex systems showing fractal geometric correlations. For models with 5880 long range interactions, such as Laplacian growth models, the 5881 identification by analytical methods of the transformation's basic 5882 elements is a very difficult task. Here we present a Monte Carlo 5883 renormalization approach which allows the direct numerical evaluation 5884 of the FST transfer matrix, overcoming the usual problems of analytical 5885 and numerical treatments. The scheme is explicitly applied to the 5886 diffusion limited aggregation case where a scale invariant regime is 5887 identified and the fractal dimension is computed. The Monte Carlo FST 5888 represents an alternative tool which can be easily generalized to other 5889 fractal growth models with nonlocal interactions. 5890 C1 INFM,UNITA ROMA 1,ROME,ITALY. 5891 LEIDEN UNIV,INST LORENTZ,NL-2300 RA LEIDEN,NETHERLANDS. 5892 RP Piccioni, M, UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,PIAZZALE ALDO MORO 5893 2,I-00185 ROME,ITALY. 5894 CR BINDER K, 1992, MONTE CARLO METHODS 5895 CAFIERO R, 1993, PHYS REV LETT, V70, P3939 5896 CALDARELLI G, 1988, PHYSICA A, V151, P207 5897 DEANGELIS R, 1991, EUROPHYS LETT, V16, P417 5898 ERZAN A, 1995, REV MOD PHYS, V67, P545 5899 EVERTSZ C, 1990, PHYS REV A, V41, P1830 5900 HANSEN A, 1990, EUROPHYS LETT, V13, P341 5901 HOSHEN J, 1976, PHYS REV B, V14, P3428 5902 PIETRONERO L, 1988, PHYSICA A, V151, P207 5903 STAUFFER D, 1985, INTRO PERCOLATION TH 5904 TREMBLAY RR, 1991, PHYS REV A, V44, P7985 5905 VICSEK T, 1992, FRACTAL GROWTH PHENO 5906 WILKINSON D, 1983, J PHYS A-MATH GEN, V16, P3365 5907 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 5908 NR 14 5909 TC 2 5910 PU AMERICAN PHYSICAL SOC 5911 PI COLLEGE PK 5912 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 5913 SN 1063-651X 5914 J9 PHYS REV E 5915 JI Phys. Rev. E 5916 PD JAN 5917 PY 1997 5918 VL 55 5919 IS 1 5920 PN Part B 5921 BP 1170 5922 EP 1173 5923 PG 4 5924 SC Physics, Fluids & Plasmas; Physics, Mathematical 5925 GA WD546 5926 UT ISI:A1997WD54600065 5927 ER 5928 5929 PT J 5930 AU Vespignani, A 5931 Zapperi, S 5932 Loreto, V 5933 TI Renormalization of nonequilibrium systems with critical stationary 5934 states 5935 SO PHYSICAL REVIEW LETTERS 5936 LA English 5937 DT Article 5938 ID FOREST-FIRE MODEL; SELF-ORGANIZED CRITICALITY; MEAN-FIELD THEORY; 5939 CRITICAL-BEHAVIOR; SANDPILE MODELS; LATTICE GAS 5940 AB We introduce the general formulation of a renormalization method 5941 suitable to study the critical properties of nonequilibrium systems 5942 with steady states: the dynamically driven renormalization group. We 5943 renormalize the time evolution operator by computing the rescaled time 5944 transition rate between coarse grained states. The obtained 5945 renormalization equations are coupled to a stationarity condition which 5946 provides the approximate nonequilibrium statistical weights of 5947 steady-state configurations to be used in the calculations. in this way 5948 we are able to write recursion relations for the parameter evolution 5949 under scale change, from which we can extract numerical values for the 5950 critical exponents. This general framework allows the systematic 5951 analysis of several models showing self-organized criticality in terms 5952 of usual concepts of phase transitions and critical phenomena. 5953 C1 BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215. 5954 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. 5955 ENEA,RES CTR,I-80055 PORTICI,NAPOLI,ITALY. 5956 RP Vespignani, A, LEIDEN UNIV,INST LORENTZ,POB 9506,NL-2300 RA 5957 LEIDEN,NETHERLANDS. 5958 CR BAK P, 1987, PHYS REV LETT, V59, P381 5959 BAK P, 1988, PHYS REV A, V38, P364 5960 BAK P, 1990, PHYS LETT A, V147, P297 5961 BAK P, 1993, FRACTALS DISORDERED, V2 5962 CHRISTENSEN K, 1993, PHYS REV LETT, V71, P2737 5963 CLAR S, 1994, PHYS REV E A, V50, P1009 5964 CRESWICK RJ, 1992, INTRO RENORMALIZATIO 5965 DICKMAN R, 1988, PHYS REV A, V38, P2588 5966 DOMB C, 1972, PHASE TRANSITION CRI, V1 5967 DOMB C, 1983, PHASE TRANSITION CRI, V7 5968 DROSSEL B, COMMUNICATION 5969 DROSSEL B, 1992, PHYS REV LETT, V69, P1629 5970 DROSSEL B, 1993, PHYS REV LETT, V71, P3739 5971 ERZAN A, 1995, REV MOD PHYS, V67, P545 5972 GRASSBERGER P, 1991, J STAT PHYS, V63, P685 5973 GRINSTEIN G, 1995, NATO ADV STUDY I B, V344 5974 IVASHKEVICH EV, 1996, PHYS REV LETT, V76, P3368 5975 KATZ S, 1983, PHYS REV B, V28, P1655 5976 KATZ S, 1984, J STAT PHYS, V34, P497 5977 KEIZER J, 1987, STAT THERMODYNAMICS 5978 LORETO V, 1995, PHYS REV LETT, V75, P465 5979 MANDELBROT BB, 1983, FRACTAL GEOMETRY NAT 5980 MOSSNER WK, 1992, PHYSICA A, V190, P205 5981 NIEMEIJER T, 1972, PHASE TRANSITIONS CR, V6 5982 PATZLAFF H, 1994, PHYS LETT A, V189, P187 5983 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 5984 SCHMITTMANN B, 1983, PHASE TRANSITION CRI, V17 5985 VESPIGNANI A, IN PRESS 5986 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 5987 VICSEK T, 1992, FRACTAL GROWTH PHENO 5988 NR 30 5989 TC 16 5990 PU AMERICAN PHYSICAL SOC 5991 PI COLLEGE PK 5992 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 5993 SN 0031-9007 5994 J9 PHYS REV LETT 5995 JI Phys. Rev. Lett. 5996 PD NOV 25 5997 PY 1996 5998 VL 77 5999 IS 22 6000 BP 4560 6001 EP 4563 6002 PG 4 6003 SC Physics, Multidisciplinary 6004 GA VU502 6005 UT ISI:A1996VU50200020 6006 ER 6007 6008 PT J 6009 AU Caldarelli, G 6010 Vespignani, A 6011 TI Fixed scale transformation approach for born model of fractures 6012 SO FRACTALS-AN INTERDISCIPLINARY JOURNAL ON THE COMPLEX GEOMETRY OF NATURE 6013 LA English 6014 DT Article 6015 ID DIFFUSION-LIMITED AGGREGATION; FRACTAL GROWTH 6016 AB We use the Fixed Scale Transformation theoretical approach to study the 6017 problem of fractal growth in fractures generated by using the Born 6018 Model. In this case the application of the method is more complex 6019 because of the vectorial nature of the model considered. In particular, 6020 one needs a careful choice of the lattice path integral for the 6021 fracture evolution and the identification of the appropriate way to 6022 take effectively into account screening effects. The good agreement of 6023 our results with computer simulations shows the validity and 6024 flexibility of the FST method in the study of fractal patterns 6025 evolution. 6026 C1 YALE UNIV,DEPT MATH,NEW HAVEN,CT 06520. 6027 RP Caldarelli, G, SCUOLA INT SUPER STUDI AVANZATI,ISAS,V BEIRUT 6028 2-4,I-34014 TRIESTE,ITALY. 6029 CR CAFIERO R, 1993, PHYS REV LETT, V70, P3939 6030 CALDARELLI G, 1994, PHYS REV E A, V49, P2673 6031 DEANGELIS R, 1991, EUROPHYS LETT, V16, P417 6032 ERZAN A, 1995, REV MOD PHYS 6033 LOUIS E, 1987, EUROPHYS LETT, V3, P871 6034 NIEMEYER L, 1984, PHYS REV LETT, V52, P1033 6035 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 6036 PIETRONERO L, 1988, PHYSICA A, V151, P207 6037 VESPIGNANI A, 1990, PHYSICA A, V168, P723 6038 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 6039 YAN H, 1989, EUROPHYS LETT, V10, P7 6040 NR 11 6041 TC 0 6042 PU WORLD SCIENTIFIC PUBL CO PTE LTD 6043 PI SINGAPORE 6044 PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE 6045 SN 0218-348X 6046 J9 FRACTALS 6047 JI Fractals-Interdiscip. J. Complex Geom. Nat. 6048 PD DEC 6049 PY 1995 6050 VL 3 6051 IS 4 6052 BP 829 6053 EP 837 6054 PG 9 6055 SC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences 6056 GA VB886 6057 UT ISI:A1995VB88600019 6058 ER 6059 6060 PT J 6061 AU Vespignani, A 6062 Petri, A 6063 Alippi, A 6064 Paparo, G 6065 Costantini, M 6066 TI Long range correlation on properties of aftershock relaxation signals 6067 SO FRACTALS-AN INTERDISCIPLINARY JOURNAL ON THE COMPLEX GEOMETRY OF NATURE 6068 LA English 6069 DT Article 6070 ID SELF-ORGANIZED CRITICALITY; ACOUSTIC-EMISSION; 1/F NOISE; MODELS 6071 AB Relaxation processes taking place after microfracturing of laboratory 6072 samples give rise to ultrasonic acoustic emission signals. Statistical 6073 analysis of the resulting time series has revealed many features which 6074 are characteristic of critical phenomena. In particular, the 6075 autocorrelation functions obey a power-law behavior, implying a power 6076 spectrum of the kind 1/f. Also the amplitude distribution N(V) of such 6077 signals follows a power law, and the obtained exponents are consistent 6078 with those found in other experiments: N(V) dV similar or equal to 6079 V--gamma dV, with gamma = 1.7 +/- 0.2. We also analyzed the 6080 distribution N(tau) of the delay time tau between two consecutive 6081 acoustic emission events. We found that a N(tau) distribution rather 6082 close to a power law constitutes a common feature of all the recorded 6083 signals. These experimental results can be considered as a striking 6084 evidence for a critical dynamics underlying the microfracturing 6085 processes. 6086 C1 YALE UNIV,DEPT MATH,NEW HAVEN,CT 06520. 6087 UNIV PERUGIA,DIPARTIMENTO FIS,IST NAZL FIS NUCL,SEZ PERUGIA,I-06100 PERUGIA,ITALY. 6088 CONSORZIO RIC GRAN SASSO,I-67010 ASSERGI,LAQUILA,ITALY. 6089 UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY. 6090 CNR,IST ACUST OM CORBINO,I-00189 ROME,ITALY. 6091 CR BAK P, 1987, PHYS REV LETT, V59, P381 6092 BAK P, 1988, PHYS REV A, V38, P364 6093 BAK P, 1989, NETURE, V342, P7800 6094 BAK P, 1993, FRACTALS DISORDERED, V2 6095 CAFIERO R, 1995, EUROPHYS LETT, V29, P111 6096 CANNELLI G, 1993, PHYS REV LETT, V70, P3923 6097 CHRISTENSEN K, 1991, J STAT PHYS, V63, P653 6098 CHRISTENSEN K, 1992, PHYS REV LETT, V68, P2417 6099 DERUBEIS V, PREPRINT 6100 DIODATI P, 1991, PHYS REV LETT, V67, P2239 6101 GUTENBERG B, 1956, ANN GEOFIS, V9, P1 6102 HIRATA T, 1987, J GEOPHYS RES-SOLID, V92, P6215 6103 HUANG J, 1988, EARTH PLANET SC LETT, V91, P223 6104 ISHIMOTO M, 1939, B EARTHQ RES I TOKYO, V17, P443 6105 KERTESZ J, 1990, J PHYS A, V23, L433 6106 LORD AE, 1981, PHYSICAL ACOUSTICS, V15 6107 MANDELBROT BB, 1983, FRACTAL GEOMETRY NAT 6108 MCDONALD DKC, 1962, NOISE FLUCTUATIONS 6109 MOGI K, 1962, B EARTHQ RES I TOKIO, V40, P815 6110 MOGI K, 1962, B EARTHQ RES I TOKYO, V40, P125 6111 MOGI K, 1963, B EARTHQ RES I TOKYO, V41, P595 6112 OMORI F, 1894, REP EARTH INV COMM, V2, P103 6113 PACZUSKI M, 1994, EUROPHYS LETT, V27, P97 6114 PETRI A, 1994, PHYS REV LETT, V73, P3423 6115 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 6116 SORNETTE D, 1994, J PHYS I, V4, P209 6117 TZSCHICHHOLZ F, 1994, PHYS REV B, V49, P15035 6118 UTSU T, 1969, J FS HOKKAIDO U 7, V3, P129 6119 VICSEK T, 1994, FRACTALS NATURAL SCI 6120 NR 29 6121 TC 8 6122 PU WORLD SCIENTIFIC PUBL CO PTE LTD 6123 PI SINGAPORE 6124 PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE 6125 SN 0218-348X 6126 J9 FRACTALS 6127 JI Fractals-Interdiscip. J. Complex Geom. Nat. 6128 PD DEC 6129 PY 1995 6130 VL 3 6131 IS 4 6132 BP 839 6133 EP 847 6134 PG 9 6135 SC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences 6136 GA VB886 6137 UT ISI:A1995VB88600020 6138 ER 6139 6140 PT J 6141 AU Loreto, V 6142 Pietronero, L 6143 Vespignani, A 6144 Zapperi, S 6145 TI Renormalization group approach for forest fire models 6146 SO FRACTALS-AN INTERDISCIPLINARY JOURNAL ON THE COMPLEX GEOMETRY OF NATURE 6147 LA English 6148 DT Article 6149 ID SELF-ORGANIZED CRITICALITY; SANDPILE MODELS 6150 AB We introduce a Renormalization scheme for the one- and two-dimensional 6151 Forest-Fire models in order to characterize the nature of the critical 6152 state and its scale invariant dynamics. We show the existence of a 6153 relevant scaling field associated with a repulsive fixed point. These 6154 models are therefore critical in the usual sense because the fixed 6155 point value of the control parameter is crucial in order to get 6156 criticality and it is not just the expression of a time scale 6157 separation. This general scheme allows us to calculate analytically the 6158 critical exponents for the one- and two-dimensional cases. The results 6159 obtained are in good agreement with exact or numerical results. 6160 C1 YALE UNIV,DEPT MATH,NEW HAVEN,CT 06520. 6161 BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215. 6162 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. 6163 RP Loreto, V, UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,PIAZZALE ALDO MORO 6164 2,I-00185 ROME,ITALY. 6165 CR BAK P, 1987, PHYS REV LETT, V59, P381 6166 BAK P, 1988, PHYS REV A, V38, P364 6167 BAK P, 1990, PHYS LETT A, V147, P297 6168 CAFIERO R, 1993, PHYS REV LETT, V70, P3939 6169 CAFIERO R, 1995, EUROPHYS LETT, V29, P111 6170 CHRISTENSEN K, 1993, PHYS REV LETT, V71, P2737 6171 CLAR S, 1994, PHYS REV E A, V50, P1009 6172 DROSSEL B, 1992, PHYS REV LETT, V69, P1629 6173 DROSSEL B, 1993, PHYS REV LETT, V71, P3739 6174 ERZAN A, UNPUB REV MOD PHYS 6175 GRASSBERGER P, 1991, J STAT PHYS, V63, P685 6176 GRASSBERGER P, 1993, J PHYS A-MATH GEN, V26, P2081 6177 LORETO V, UNPUB J PHYS 6178 MOSSNER WK, 1992, PHYSICA A, V190, P205 6179 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 6180 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 6181 NR 16 6182 TC 1 6183 PU WORLD SCIENTIFIC PUBL CO PTE LTD 6184 PI SINGAPORE 6185 PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE 6186 SN 0218-348X 6187 J9 FRACTALS 6188 JI Fractals-Interdiscip. J. Complex Geom. Nat. 6189 PD SEP 6190 PY 1995 6191 VL 3 6192 IS 3 6193 BP 445 6194 EP 452 6195 PG 8 6196 SC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences 6197 GA VB883 6198 UT ISI:A1995VB88300005 6199 ER 6200 6201 PT J 6202 AU Loreto, V 6203 Vespignani, A 6204 Zapperi, S 6205 TI Renormalization scheme for forest-fire models 6206 SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL 6207 LA English 6208 DT Article 6209 ID SELF-ORGANIZED CRITICALITY; DIFFUSION-LIMITED AGGREGATION; PERCOLATION 6210 AB We introduce a renormalization scheme for forest-fire models in order 6211 to characterize the nature of the critical state and its 6212 scale-invariant dynamics. We study one- and two-dimensional models 6213 defining a characterization of the phase space that allows us to 6214 describe the evolution of the dynamics under a scale transformation. We 6215 show the existence of a relevant critical parameter associated with a 6216 repulsive fixed point in the phase space, From the 6217 renormalization-group point of view these models are therefore critical 6218 in the usual sense, because the fixed-point value of the control 6219 parameter is crucial in order to get criticality. This general scheme 6220 allows us to calculate analytically the critical exponent nu which 6221 describes the approach to the critical point along the repulsive 6222 direction and the exponent tau that characterizes the distribution of 6223 forest clusters at the critical point. We obtain nu = 1.0, tau = 1.0 6224 and nu = 0.65, tau = 1.16, respectively, for the one- and 6225 two-dimensional cases, in very good agreement with exact and numerical 6226 results. 6227 C1 LEIDEN UNIV,INST LORENTZ,2300 RA LEIDEN,NETHERLANDS. 6228 BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215. 6229 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. 6230 RP Loreto, V, UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,PIAZZALE A MORO 6231 2,I-00185 ROME,ITALY. 6232 CR BAK P, 1987, PHYS REV LETT, V59, P381 6233 BAK P, 1988, PHYS REV A, V38, P364 6234 BAK P, 1989, J GEOPHYS RES-SOLID, V94, P15635 6235 BAK P, 1990, PHYS LETT A, V147, P297 6236 BAK P, 1993, PHYS REV LETT, V71, P4083 6237 BAK P, 1993, RICERCHE ECONOMICHE, V47, P3 6238 BENHUR A, 1996, UNPUB PHYS REV E 6239 CAFIERO R, 1993, PHYS REV LETT, V70, P3939 6240 CHRISTENSEN K, 1993, PHYS REV LETT, V71, P2737 6241 CLAR S, 1994, PHYS REV E A, V50, P1009 6242 DROSSEL B, 1992, PHYS REV LETT, V69, P1629 6243 DROSSEL B, 1993, PHYS REV LETT, V71, P3739 6244 DROSSEL B, 1994, PHYSICA A, V204, P212 6245 ERZAN A, 1995, REV MOD PHYS, V67, P545 6246 GRASSBERGER P, 1991, J STAT PHYS, V63, P685 6247 GRASSBERGER P, 1993, J PHYS A-MATH GEN, V26, P2081 6248 HENLEY CL, 1993, PHYS REV LETT, V71, P2741 6249 LORETO V, 1995, PHYS REV LETT, V75, P465 6250 MOSSNER WK, 1992, PHYSICA A, V190, P205 6251 NIEMEYER L, 1984, PHYS REV LETT, V52, P1033 6252 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 6253 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 6254 VESPIGNANI A, UNPUB J STAT PHYS 6255 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 6256 WILKINSON D, 1983, J PHYS A-MATH GEN, V16, P3365 6257 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 6258 NR 26 6259 TC 9 6260 PU IOP PUBLISHING LTD 6261 PI BRISTOL 6262 PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX 6263 SN 0305-4470 6264 J9 J PHYS-A-MATH GEN 6265 JI J. Phys. A-Math. Gen. 6266 PD JUN 21 6267 PY 1996 6268 VL 29 6269 IS 12 6270 BP 2981 6271 EP 3004 6272 PG 24 6273 SC Physics, Multidisciplinary; Physics, Mathematical 6274 GA UU803 6275 UT ISI:A1996UU80300008 6276 ER 6277 6278 PT J 6279 AU KAUFMAN, H 6280 VESPIGNANI, A 6281 MANDELBROT, BB 6282 WOOG, L 6283 TI PARALLEL DIFFUSION-LIMITED AGGREGATION 6284 SO PHYSICAL REVIEW E 6285 LA English 6286 DT Article 6287 ID OFF-LATTICE; CLUSTERS; DLA 6288 AB We present methods for simulating very large diffusion-limited 6289 aggregation (DLA) clusters using parallel processing (PDLA). With our 6290 techniques, we have been able to simulate clusters of up to 130 million 6291 particles. The time required for generating a 100 million particle PDLA 6292 is approximately 13 h. The fractal behavior of these ''parallel'' 6293 clusters changes from a multiparticle aggregation dynamics to the usual 6294 DLA dynamics. The transition is described by simple scaling assumptions 6295 that define a characteristic cluster size separating the two dynamical 6296 regimes. We also use DLA clusters as seeds for parallel processing. In 6297 this case, the transient regime disappears and the dynamics converges 6298 from the early stage to that of DLA. 6299 C1 IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598. 6300 RP KAUFMAN, H, YALE UNIV,DEPT MATH,NEW HAVEN,CT 06520. 6301 CR AMITRANO C, 1993, FRACTALS, V1, P840 6302 CAFIERO R, 1993, PHYS REV LETT, V70, P3939 6303 EVERTSZ C, 1990, PHYS REV A, V41, P1830 6304 FOLEY J, 1990, COMPUTER GRAPHICS PR 6305 HALSEY TC, 1994, PHYS REV LETT, V72, P1228 6306 MANDELBROT BB, 1992, PHYSICA A, V191, P95 6307 MANDELBROT BB, 1995, EUROPHYS LETT, V29, P599 6308 MEAKIN P, 1988, PHASE TRANSITIONS CR, V12, P335 6309 OSSADNIK P, 1992, PHYS REV A, V45, P1058 6310 OSSADNIK P, 1993, PHYSICA A, V195, P319 6311 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 6312 TOLMAN S, 1989, PHYS REV A, V40, P428 6313 VICSEK T, 1992, FRACTAL GROWTH PHENO 6314 VICSEK T, 1994, FRACTALS NATURAL SCI 6315 VOSS RF, 1984, PHYS REV B, V30, P334 6316 VOSS RF, 1993, FRACTALS, V1, P141 6317 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 6318 YEKUTIELI I, 1994, J PHYS A-MATH GEN, V27, P275 6319 NR 18 6320 TC 16 6321 PU AMERICAN PHYSICAL SOC 6322 PI COLLEGE PK 6323 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 6324 SN 1063-651X 6325 J9 PHYS REV E 6326 JI Phys. Rev. E 6327 PD NOV 6328 PY 1995 6329 VL 52 6330 IS 5 6331 PN Part B 6332 BP 5602 6333 EP 5609 6334 PG 8 6335 SC Physics, Fluids & Plasmas; Physics, Mathematical 6336 GA TG337 6337 UT ISI:A1995TG33700057 6338 ER 6339 6340 PT J 6341 AU PIETRONERO, L 6342 VESPIGNANI, A 6343 TI FRACTALS, SELF-ORGANIZED-CRITICALITY AND THE FIXED SCALE TRANSFORMATION 6344 SO CHAOS SOLITONS & FRACTALS 6345 LA English 6346 DT Article 6347 AB DLA Fractal growth models and the sand pile models are both 6348 characterized by a non linear irreversible dynamics that evolves 6349 spontaneously in a critical state. These phenomena pose questions of 6350 new type for which novel theoretical concepts are necessary. We argue 6351 that the approach of the Fixed Scale Transformation contains some of 6352 the essential theoretical elements to treat these problems and to 6353 compute their properties analytically. Its original application to 6354 DLA-like problems has been made more systematic by the analysis of the 6355 scale invariant growth dynamics. Recently these concepts have been also 6356 developed for an analytical study of the critical properties of 6357 sandpile models. 6358 RP PIETRONERO, L, UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,PIAZZALE A MORO 6359 2,I-00185 ROME,ITALY. 6360 CR BAK P, 1987, PHYS REV LETT, V59, P381 6361 CAFIERO R, 1993, PHYS REV LETT, V70, P3939 6362 CRESWICK RJ, 1992, RENORMALIZATION GROU 6363 MANNA SS, 1991, J PHYS A, V24, L363 6364 PIETRONERO L, PREPRINT 6365 PIETRONERO L, UNPUB REV MODERN PHY 6366 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 6367 PIETRONERO L, 1991, PHYS REV LETT, V66, P2336 6368 VICSEK T, 1992, FRACTAL GROWTH PHENO 6369 NR 9 6370 TC 2 6371 PU PERGAMON-ELSEVIER SCIENCE LTD 6372 PI OXFORD 6373 PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB 6374 SN 0960-0779 6375 J9 CHAOS SOLITON FRACTAL 6376 JI Chaos Solitons Fractals 6377 PY 1995 6378 VL 6 6379 BP 471 6380 EP 480 6381 PG 10 6382 SC Mathematics, Interdisciplinary Applications; Physics, 6383 Multidisciplinary; Physics, Mathematical 6384 GA TF140 6385 UT ISI:A1995TF14000054 6386 ER 6387 6388 PT J 6389 AU ZARATTI, F 6390 RUIZ, I 6391 PIETRONERO, L 6392 VESPIGNANI, A 6393 TI FIXED SCALE TRANSFORMATION APPLIED TO FRACTAL AGGREGATION WITH LEVY 6394 FLIGHT PARTICLE TRAJECTORIES 6395 SO CHAOS SOLITONS & FRACTALS 6396 LA English 6397 DT Article 6398 ID DIFFUSION-LIMITED AGGREGATION 6399 AB We extend the Fixed Scale Transformation (FST) method, developed for 6400 Laplacian fractal growth, to the case of aggregation phenomena based on 6401 diffusing particles following Levy-flight walk. We compute analytically 6402 the clusters fractal dimension for different values of the exponent 6403 governing the Levy-flight trajectories. The results obtained are in 6404 very good agreement with the numerical simulations and show 6405 analytically how the different screening effects present in the 6406 Levy-flight diffusion change the aggregates fractal dimension. 6407 C1 UNIV TOMAS FRIAS,DEPT FIS,POTOSI,BOLIVIA. 6408 UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY. 6409 RP ZARATTI, F, UNIV MAYOR SAN ANDRES,INST INVEST FIS,LA PAZ,BOLIVIA. 6410 CR CAFIERO R, 1993, PHYS REV LETT, V70, P3939 6411 ERZAN A, 1994, REV MOD PHYS 6412 MEAKIN P, 1984, KINETICS AGGREGATION 6413 MEAKIN P, 1984, PHYS REV B, V29, P3722 6414 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 6415 PIETRONERO L, 1995, CHAOS SOLITON FRACT, V6, P471 6416 VICSEK T, 1991, FRACTAL GROWTH PHENO 6417 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 6418 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 6419 ZARATTI F, 1993, PREPRINT 6420 NR 10 6421 TC 0 6422 PU PERGAMON-ELSEVIER SCIENCE LTD 6423 PI OXFORD 6424 PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB 6425 SN 0960-0779 6426 J9 CHAOS SOLITON FRACTAL 6427 JI Chaos Solitons Fractals 6428 PY 1995 6429 VL 6 6430 BP 585 6431 EP 591 6432 PG 7 6433 SC Mathematics, Interdisciplinary Applications; Physics, 6434 Multidisciplinary; Physics, Mathematical 6435 GA TF140 6436 UT ISI:A1995TF14000066 6437 ER 6438 6439 PT J 6440 AU MANDELBROT, BB 6441 VESPIGNANI, A 6442 KAUFMAN, H 6443 TI CROSSCUT ANALYSIS OF LARGE RADIAL DLA - DEPARTURES FROM SELF-SIMILARITY 6444 AND LACUNARITY EFFECTS 6445 SO EUROPHYSICS LETTERS 6446 LA English 6447 DT Article 6448 ID DIFFUSION-LIMITED AGGREGATION; DIELECTRIC-BREAKDOWN; ACTIVE ZONE; 6449 CLUSTERS; MODEL 6450 AB In order to understand better the morphology and the asymptotic 6451 behavior in Diffusion-Limited Aggregation (DLA), we studied a large 6452 number of very large off-lattice circular clusters. We inspected both 6453 dynamical and geometric asymptotic properties via the scaling behavior 6454 of the transverse growth crosscuts, ie. the one-dimensional cuts by 6455 circles. The emerging picture corresponds qualitatively and 6456 quantitatively to the scenario of infinite drift that starts from the 6457 familiar five-armed shape for small sizes and proceeds through 6458 increasingly tight multi-armed shapes. The transverse crosscuts show 6459 quantitatively how the lacunarity of circular clusters becomes 6460 increasingly compact with size. Finally, we find the transverse-cut 6461 dimensions to be in agreement for clusters grown in circular and 6462 cylindrical geometry, suggesting that the question of universality is 6463 best addressed on the crosscut. 6464 C1 IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598. 6465 RP MANDELBROT, BB, YALE UNIV,DEPT MATH,NEW HAVEN,CT 06520. 6466 CR AMITRANO C, 1993, FRACTALS, V1, P840 6467 ARNEODO A, 1992, PHYS REV LETT, V68, P3456 6468 ERZAN A, 1995, REV MOD PHYS, V67, P545 6469 EVERTSZ C, 1990, PHYS REV A, V41, P1830 6470 HALSEY TC, 1992, PHYS REV A, V46, P7793 6471 MANDELBROT BB, 1982, FRACTAL GEOMETRY NAT 6472 MANDELBROT BB, 1992, PHYSICA A, V191, P95 6473 MANDELBROT BB, 1994, J PHYS A, V27, L237 6474 MANDELBROT BB, 1995, EUROPHYS LETT, V29, P599 6475 MANDELBROT BB, 1995, FRACTAL GEOMETRY STO 6476 MEAKIN P, 1988, PHASE TRANSITIONS CR, V12, P335 6477 NIEMEYER L, 1984, PHYS REV LETT, V52, P1033 6478 OSSADNIK P, 1993, PHYSICA A, V195, P319 6479 PICCIONI M, UNPUB 6480 PLISCHKE M, 1984, PHYS REV LETT, V53, P415 6481 VICSEK T, 1989, FRACTAL GROWTH PHENO 6482 VOSS RF, 1993, FRACTALS, V1, P141 6483 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 6484 YEKUTIELI L, 1994, J PHYS A, V27, P275 6485 NR 19 6486 TC 18 6487 PU EDITIONS PHYSIQUE 6488 PI LES ULIS CEDEX 6489 PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, 6490 FRANCE 6491 SN 0295-5075 6492 J9 EUROPHYS LETT 6493 JI Europhys. Lett. 6494 PD OCT 20 6495 PY 1995 6496 VL 32 6497 IS 3 6498 BP 199 6499 EP 204 6500 PG 6 6501 SC Physics, Multidisciplinary 6502 GA TC610 6503 UT ISI:A1995TC61000002 6504 ER 6505 6506 PT J 6507 AU ERZAN, A 6508 PIETRONERO, L 6509 VESPIGNANI, A 6510 TI THE FIXED-SCALE TRANSFORMATION APPROACH TO FRACTAL GROWTH 6511 SO REVIEWS OF MODERN PHYSICS 6512 LA English 6513 DT Review 6514 ID DIFFUSION-LIMITED-AGGREGATION; RENORMALIZATION-GROUP-APPROACH; 6515 SELF-ORGANIZED CRITICALITY; DIELECTRIC-BREAKDOWN MODEL; CLUSTER-CLUSTER 6516 AGGREGATION; REGGEON FIELD-THEORY; STATE POTTS-MODEL; DIRECTED 6517 PERCOLATION; INVASION PERCOLATION; CRITICAL EXPONENTS 6518 AB Irreversible fractal-growth models like diffusion-limited aggregation 6519 (DLA) and the dielectric breakdown model (DBM) have confronted us with 6520 theoretical problems of a new type for which standard concepts like 6521 field theory and renormalization group do not seem to be suitable. The 6522 fixed-scale transformation (FST) is a theoretical scheme of a novel 6523 type that can deal with such problems in a reasonably systematic way. 6524 The main idea is to focus on the irreversible dynamics at a given scale 6525 and to compute accurately the nearest-neighbor correlations at this 6526 scale by suitable lattice path integrals. The next basic step is to 6527 identify the scale-invariant dynamics that refers to coarse-grained 6528 variables of arbitrary scale. The use of scale-invariant growth rules 6529 allows us to generalize these correlations to coarse-grained cells of 6530 any size and therefore to compute the fractal dimension. The basic 6531 point is to split the long-time limit (t-->infinity) for the dynamical 6532 process at a given scale that produces the asymptotically frozen 6533 structure, from the large-scale limit (r-->infinity) which defines the 6534 scale-invariant dynamics. In addition, by working at a fixed scale with 6535 respect to dynamical evolution, it is possible to include the 6536 fluctuations of boundary conditions and to reach;a remarkable level of 6537 accuracy for a real-space method. This new framework is able to explain 6538 the self-organized critical nature and the origin of fractal structures 6539 in irreversible-fractal-growth models, it also provides a rather 6540 systematic procedure for the analytical calculation of the fractal 6541 dimension and other critical exponents. The FST method can be naturally 6542 extended to a variety of equilibrium and nonequilibrium models that 6543 generate fractal structures. 6544 C1 UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY. 6545 LEIDEN UNIV,INST LORENTZ,2300 RA LEIDEN,NETHERLANDS. 6546 RP ERZAN, A, ISTANBUL TECH UNIV,FAC SCI & LETTERS,DEPT PHYS,ISTANBUL 6547 80626,TURKEY. 6548 CR ABARBANEL HDI, 1976, PHYS REV D, V14, P632 6549 AMIT DJ, 1978, FIELD THEORY RENORMA 6550 ARNEODO A, 1988, PHYS REV LETT, V61, P2281 6551 ARNEODO A, 1989, PHYS REV LETT, V63, P984 6552 BAK P, 1987, PHYS REV LETT, V59, P381 6553 BAK P, 1988, PHYS REV A, V38, P364 6554 BAK P, 1993, PHYS REV LETT, V71, P4083 6555 BALL RC, 1984, PHYS REV A, V29, P2966 6556 BARKER PW, 1990, PHYS REV A, V42, P6289 6557 BAXTER RJ, 1988, J PHYS A, V21, P3193 6558 BENAVRAHAM D, 1991, PHYS REV A, V43, P7093 6559 BENZI R, 1984, J PHYS A-MATH GEN, V17, P3521 6560 BLUMENFELD R, 1989, PHYS REV LETT, V62, P2927 6561 BOHR T, 1988, EUROPHYS LETT, V6, P445 6562 BURKHARDT TW, 1982, REAL SPACE RENORMALI 6563 CAFIERO R, 1993, PHYS REV LETT, V70, P3939 6564 CALDARELLI G, 1994, PHYS REV E A, V49, P2673 6565 CALDARELLI G, 1995, PHYSICA A, V215, P223 6566 CARDY JL, 1980, J PHYS A, V13, L423 6567 CHAYES JT, 1986, CRITICAL PHENOMENA R, P1090 6568 CHENDLER R, 1982, J FLUID MECH, V119, P249 6569 COLEMAN PH, 1992, PHYS REP, V213, P311 6570 CONIGLIO A, 1980, J PHYS A, V13, P2775 6571 CONIGLIO A, 1982, J PHYS A, V15, P1873 6572 CONIGLIO A, 1986, PHYS REV LETT, V57, P1016 6573 CONIGLIO A, 1989, PHYS REV LETT, V62, P3054 6574 CONIGLIO A, 1990, PHYSICA A, V163, P325 6575 DEANGELIS R, 1991, EUROPHYS LETT, V16, P417 6576 DEDOMINICIS C, 1975, LETT NUOVO CIMENTO, V12, P567 6577 DEDOMINICIS C, 1975, PHYS REV B, V12, P4945 6578 DEDOMINICIS C, 1976, J PHYS-PARIS, V37, P247 6579 DEDOMINICIS C, 1977, PHYS REV B, V18, P353 6580 DEDOMINICIS C, 1977, PHYS REV LETT, V38, P505 6581 DEGENNES PG, 1979, SCALING CONCEPTS POL 6582 DENNIJS M, 1983, PHYS REV B, V27, P1674 6583 DENNIJS MPM, 1979, J PHYS A, V12, P1857 6584 DERRIDA B, 1985, J PHYS-PARIS, V46, P1623 6585 DICKMAN R, 1986, PHYS REV A, V34, P4246 6586 DISTASIO M, 1994, J PHYS A-MATH GEN, V27, P317 6587 DUPLANTIER B, 1989, PHYS REV LETT, V63, P2536 6588 ECKMANN JP, 1989, PHYS REV A, V29, P3185 6589 ECKMANN JP, 1990, PHYS REV LETT, V65, P52 6590 EDEN M, 1961, 4TH P BERK S MATH ST, V4, P223 6591 ELDERFIELD D, 1985, J PHYS A, V18, P2591 6592 ELDERFIELD D, 1985, J PHYS A-MATH GEN, V18, L767 6593 ELDERFIELD D, 1985, J PHYS A-MATH GEN, V18, L773 6594 ERZAN A, 1991, J PHYS A, V24, P1875 6595 ERZAN A, 1991, PHYS REV LETT, V66, P2750 6596 ERZAN A, 1992, EUROPHYS LETT, V20, P595 6597 ERZAN A, 1992, PHYSICA A, V185, P66 6598 ESSAM JW, 1988, J PHYS A, V21, P3815 6599 EVERTSZ C, 1989, THESIS U GRONINGEN 6600 EVERTSZ C, 1990, PHYS REV A, V41, P1830 6601 FEDER J, 1988, FRACTALS 6602 FISHER ME, 1967, REP PROGR PHYS, V30, P615 6603 FURNBERG L, 1988, PHYS REV LETT, V61, P2117 6604 GLAUBER RJ, 1963, J MATH PHYS, V4, P294 6605 GRASSBERGER P, 1979, ANN PHYS-NEW YORK, V122, P373 6606 GRASSBERGER P, 1982, Z PHYS B, V47, P465 6607 GRASSBERGER P, 1986, FRACTALS PHYSICS, P273 6608 GRASSBERGER P, 1992, J PHYS A-MATH GEN, V25, P5475 6609 GUNTON JD, 1979, LECTURE NOTES PHYSIC, V1, P104 6610 GUOLD H, 1983, PHYS REV LETT, V50, P686 6611 HALPERIN BI, 1972, PHYS REV LETT, V29, P1548 6612 HALPINHEALY T, 1955, PHYS REP, V254, P215 6613 HALSEY TC, 1992, PHYS REV A, V46, P7793 6614 HALSEY TC, 1994, PHYS REV LETT, V72, P1228 6615 HOHENBERG PC, 1977, REV MOD PHYS, V49, P425 6616 HOLSCHNEIDER M, 1988, J STAT PHYS, V50, P953 6617 HONDA K, 1986, J PHYS SOC JPN, V55, P707 6618 HUNER M, 1994, PHYSICA A, V212, P314 6619 JANSSEN HK, 1979, LECT NOTE PHYS, V104, P26 6620 JULLIEN R, 1987, AGGREGATIONN FRACTAL 6621 KADANOFF LP, 1967, REV MOD PHYS, V39, P395 6622 KANEKO K, 1985, COLLAPSE TORI GENESI 6623 KARDAR M, 1986, PHYS REV LETT, V56, P889 6624 KERTESZ J, 1986, J PHYS A, V19, L257 6625 KINZEL W, 1983, ANN ISRAEL PHYSICAL, V5, P425 6626 KIRKALDY JS, 1992, REP PROG PHYS, V55, P723 6627 KOLB M, 1983, PHYS REV LETT, V51, P1123 6628 LEYVRAZ F, 1986, GROWTH FORM, P136 6629 LIGGETT TM, 1985, INTERACTING PARTICLE 6630 LUIS E, 1987, EUROPHYS LETT, V3, P871 6631 MANDELBROT BB, 1974, J FLUID MECH, V62, P331 6632 MANDELBROT BB, 1982, FRACTAL GEOMETRY NAT 6633 MANDELBROT BB, 1990, NATURE, V348, P143 6634 MANDELBROT BB, 1992, PHYSICA A, V191, P95 6635 MANDELBROT BB, 1995, IN PRESS EUROPHYS LE 6636 MARSILI M, 1991, PHYSICA A, V175, P9 6637 MARSILI M, 1994, J STAT PHYS, V77, P733 6638 MAZENKO GF, 1979, LECTURE NOTES PHYSIC, V104, P97 6639 MEAKIN P, 1983, PHYS REV LETT, V51, P1119 6640 MEAKIN P, 1984, PHYS REV B, V29, P3722 6641 MEAKIN P, 1988, PHASE TRANSITIONS CR, V12, P335 6642 MEAKIN P, 1989, FRACTALS PHYSICAL OR, P137 6643 MEINHARDT H, 1992, REP PROG PHYS, V55, P797 6644 MIGDAL AA, 1974, PHYS LETT B, V48, P239 6645 MIGDAL AA, 1974, ZH EKSP TEOR FIZ, V67, P84 6646 MOUKARZEL C, 1992, PHYSICA A, V188, P469 6647 MUTHUKUMAR M, 1983, PHYS REV LETT, V50, P839 6648 NAGATANI T, 1987, J PHYS A, V20, L381 6649 NAGATANI T, 1987, PHYS REV A, V36, P5812 6650 NICOLIS G, 1977, SELF ORG NONEQUILIBR 6651 NIEMEYER L, 1984, PHYS REV LETT, V52, P1038 6652 NITTMANN J, 1986, NATURE, V321, P663 6653 OHONO K, 1992, PHYS REV A, V46, P3400 6654 OSSADNIK P, 1992, PHYS REV A, V45, P1058 6655 PALADIN G, 1987, PHYS REP, V156, P145 6656 PARISI G, 1985, J STAT PHYS, V41, P1 6657 PELITI L, 1985, J PHYS-PARIS, V46, P1469 6658 PICCIONI M, 1995, UNPUB 6659 PIETRONERO L, 1984, J STAT PHYS, V36, P811 6660 PIETRONERO L, 1986, FRACTALS PHYSICS 6661 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 6662 PIETRONERO L, 1988, PHYSICA A, V151, P207 6663 PIETRONERO L, 1990, PHYS REV A, V42, P7496 6664 PIETRONERO L, 1990, PHYSICA A, V170, P64 6665 PIETRONERO L, 1990, PHYSICA A, V170, P81 6666 PIETRONERO L, 1991, PHYS REV LETT, V66, P2336 6667 PIETRONERO L, 1991, PHYSICA A, V173, P22 6668 PIETRONERO L, 1993, FRACTALS, V1, P41 6669 PIETRONERO L, 1993, J FRACTALS, V1, P650 6670 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 6671 PIETRONERO L, 1995, PREPRINT 6672 PIETRONERO L, 1995, STOCHASTIC PROCESSES, P581 6673 RINTOUL MD, 1992, J PHYS A, V25, L945 6674 ROUX S, 1989, J PHYS A, V19, P3693 6675 SCHLOGL F, 1972, Z PHYS, V253, P147 6676 SCHWARZER S, 1990, PHYS REV LETT, V65, P603 6677 SHAPIR Y, 1986, J PHYS PARIS LETT, V46, L529 6678 SIDORETTI S, 1992, PHYSICA A, V185, P202 6679 SIEBESMA AP, 1988, PHYSICA A, V156, P613 6680 SMOLUCHOWSKI MV, 1916, PHYS Z, V17, P585 6681 STANLEY HE, 1971, INTRO PHASE TRANSITI 6682 STANLEY HE, 1982, REAL SPACE RENORMALI 6683 STANLEY HE, 1986, GROWTH FORM FRACTAL 6684 STAUFFER D, 1985, INTRO PERCOLATION TH 6685 STELL G, 1987, PHASE TRANSITIONS CR, P205 6686 STELLA AL, 1989, PHYS REV LETT, V62, P1067 6687 SUZUKI M, 1979, LECTURE NOTES PHYSIC, V104, P75 6688 SYKES MF, 1972, J PHYS A, V5, P653 6689 TANG C, 1988, PHYS REV LETT, V60, P2347 6690 TREMBLAY RR, 1989, PHYS REV A, V40, P5377 6691 TURKEVICH LA, 1985, PHYS REV LETT, V55, P1026 6692 VANDERZANDE C, 1992, PHYSICA A, V185, P235 6693 VANNIMENUS J, 1984, PHYS REV B, V30, P391 6694 VESPIGNANI A, 1990, PHYSICA A, V168, P723 6695 VESPIGNANI A, 1991, PHYSICA A, V173, P1 6696 VESPIGNANI A, 1993, FRACTALS, V1, P1002 6697 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 6698 VICSEK T, 1984, PHYS REV LETT, V52, P1669 6699 VICSEK T, 1985, PHYS REV A, V32, P1122 6700 VICSEK T, 1992, FRACTAL GROWTH PHENO 6701 WANG XR, 1989, J PHYS A, V22, L507 6702 WANG XR, 1989, PHYS REV A, V39, P5974 6703 WATTS MG, 1975, J PHYS A, V8, P61 6704 WHITE SR, 1992, PHYS REV LETT, V68, P3487 6705 WILKINSON D, 1983, J PHYS A-MATH GEN, V16, P3365 6706 WILSON KG, 1974, PHYS REP, V12, P75 6707 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 6708 WITTEN TA, 1983, PHYS REV B, V27, P5685 6709 WOLFRAM S, 1983, REV MOD PHYS, V55, P601 6710 WOLFRAM S, 1983, REV MOD PHYS, V55, P601 6711 YAN H, 1989, EUROPHYS LETT, V10, P7 6712 ZARATTI F, 1995, UNPUB 6713 ZHANG YC, 1989, PHYS REV LETT, V63, P473 6714 ZIFF RM, 1992, PHYS REV LETT, V69, P2670 6715 NR 167 6716 TC 85 6717 PU AMERICAN PHYSICAL SOC 6718 PI COLLEGE PK 6719 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 6720 SN 0034-6861 6721 J9 REV MOD PHYS 6722 JI Rev. Mod. Phys. 6723 PD JUL 6724 PY 1995 6725 VL 67 6726 IS 3 6727 BP 545 6728 EP 604 6729 PG 60 6730 SC Physics, Multidisciplinary 6731 GA RW066 6732 UT ISI:A1995RW06600001 6733 ER 6734 6735 PT J 6736 AU LORETO, V 6737 PIETRONERO, L 6738 VESPIGNANI, A 6739 ZAPPERI, S 6740 TI RENORMALIZATION-GROUP APPROACH TO THE CRITICAL-BEHAVIOR OF THE 6741 FOREST-FIRE MODEL 6742 SO PHYSICAL REVIEW LETTERS 6743 LA English 6744 DT Article 6745 ID SELF-ORGANIZED CRITICALITY 6746 AB We introduce a renormalization scheme for the one- and two-dimensional 6747 forest-fire model in order to characterize the nature of the critical 6748 state and its scale invariant dynamics. We show the existence of a 6749 relevant scaling field associated with a repulsive fixed point. This 6750 model is therefore critical in the usual sense because the control 6751 parameter has to be tuned to its critical value in order to get 6752 criticality. It turns out that this is not just the condition for a 6753 time scale separation. The critical exponents are computed analytically 6754 and we obtain nu = 1.0, tau = 1.0 and nu = 0.65, tau = 1.16, 6755 respectively, for the one- and two-dimensional cases, in very good 6756 agreement with numerical simulations. 6757 C1 LEIDEN UNIV,INST LORENTZ,2300 RA LEIDEN,NETHERLANDS. 6758 BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215. 6759 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. 6760 RP LORETO, V, UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,PIAZZALE ALDO MORO 6761 2,I-00185 ROME,ITALY. 6762 CR BAK P, 1987, PHYS REV LETT, V59, P381 6763 BAK P, 1988, PHYS REV A, V38, P364 6764 BAK P, 1990, PHYS LETT A, V147, P297 6765 CAFIERO R, 1993, PHYS REV LETT, V70, P3939 6766 CAFIERO R, 1995, EUROPHYS LETT, V29, P111 6767 CHRISTENSEN K, 1993, PHYS REV LETT, V71, P2737 6768 CLAR S, 1994, PHYS REV E A, V50, P1009 6769 DROSSEL B, 1992, PHYS REV LETT, V69, P1629 6770 DROSSEL B, 1993, PHYS REV LETT, V71, P3739 6771 DROSSEL B, 1994, PHYSICA A, V204, P212 6772 ERZAN A, IN PRESS FIXED SCALE 6773 GRASSBERGER P, 1991, J STAT PHYS, V63, P685 6774 GRASSBERGER P, 1993, J PHYS A-MATH GEN, V26, P2081 6775 LORETO V, IN PRESS RENORMALIZE 6776 MOSSNER WK, 1992, PHYSICA A, V190, P205 6777 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 6778 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 6779 VESPIGNANI A, 1995, PHYS REV E, V51, P1711 6780 NR 18 6781 TC 33 6782 PU AMERICAN PHYSICAL SOC 6783 PI COLLEGE PK 6784 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 6785 SN 0031-9007 6786 J9 PHYS REV LETT 6787 JI Phys. Rev. Lett. 6788 PD JUL 17 6789 PY 1995 6790 VL 75 6791 IS 3 6792 BP 465 6793 EP 468 6794 PG 4 6795 SC Physics, Multidisciplinary 6796 GA RK330 6797 UT ISI:A1995RK33000028 6798 ER 6799 6800 PT J 6801 AU CALDARELLI, G 6802 VESPIGNANI, A 6803 PIETRONERO, L 6804 TI FIXED SCALE TRANSFORMATION FOR FRACTURE GROWTH-PROCESSES GOVERNED BY 6805 VECTORIAL FIELDS 6806 SO PHYSICA A 6807 LA English 6808 DT Article 6809 ID DIFFUSION-LIMITED AGGREGATION 6810 AB We use the Fixed Scale Transformation (FST) approach to study the 6811 problem of fractal growth in fracture patterns generated by using the 6812 Born Model, The application of the method to this model is very complex 6813 because of the vectorial nature of the system considered. In 6814 particular, the implementation of this scheme requires a careful choice 6815 of the fracture path and the identification of the appropriate way to 6816 take into account screening effects, The good agreements of our results 6817 with computer simulations shows the validity and flexibility of the FST 6818 method which represents a general theoretical approach for the study of 6819 fractal patterns evolution. 6820 C1 YALE UNIV,DEPT MATH,NEW HAVEN,CT 06520. 6821 UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY. 6822 RP CALDARELLI, G, ISAS,SISSA,V BEIRUT 2-4,I-34014 GRIGNANO TRIESTE,ITALY. 6823 CR CAFIERO R, 1993, PHYS REV LETT, V70, P3939 6824 CALDARELLI G, 1994, PHYS REV E A, V49, P2673 6825 DEANGELIS R, 1991, EUROPHYS LETT, V16, P417 6826 ERZAN A, 1995, REV MOD PHYS 6827 HERRING RD, 1990, SCH COUNSELOR, V38, P13 6828 LOUIS E, 1987, EUROPHYS LETT, V3, P871 6829 NIEMEYER L, 1984, PHYS REV LETT, V52, P1033 6830 PIETRONERO L, 1987, PHYSICA A, V151, P207 6831 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 6832 VESPIGNANI A, 1990, PHYSICA A, V168, P723 6833 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 6834 YAN H, 1989, EUROPHYS LETT, V10, P7 6835 NR 12 6836 TC 1 6837 PU ELSEVIER SCIENCE BV 6838 PI AMSTERDAM 6839 PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS 6840 SN 0378-4371 6841 J9 PHYSICA A 6842 JI Physica A 6843 PD MAY 1 6844 PY 1995 6845 VL 215 6846 IS 3 6847 BP 223 6848 EP 232 6849 PG 10 6850 SC Physics, Multidisciplinary 6851 GA QX194 6852 UT ISI:A1995QX19400001 6853 ER 6854 6855 PT J 6856 AU MANDELBROT, BB 6857 KAUFMAN, H 6858 VESPIGNANI, A 6859 YEKUTIELI, I 6860 LAM, CH 6861 TI DEVIATIONS FROM SELF-SIMILARITY IN PLANE DLA AND THE INFINITE DRIFT 6862 SCENARIO 6863 SO EUROPHYSICS LETTERS 6864 LA English 6865 DT Article 6866 ID DIFFUSION-LIMITED AGGREGATION; ACTIVE ZONE; GROWING CLUSTERS; EDEN MODEL 6867 AB The behavior of very large clusters of diffusion-limited aggregation 6868 (DLA) was investigated to help discriminate between the two geometric 6869 scenarios recently described by Mandelbrot: finite transient and 6870 infinite drift. Using 50 DLA clusters of I million particles, we follow 6871 the increase during growth of the maximum radius of the clusters and of 6872 various relative moments. One can distinguish two regions: an inactive 6873 completely grown core and an active growing region. In the growing 6874 region, scale factors were defined the moments of the atoms distances 6875 from the original ''seed''. They do not cross-over to the behavior 6876 characteristic of self-similarity for finite sizes and support the 6877 novel ''drift'', scenario that postulate an infinite continuing 6878 ''transient''. The moment's ''misbehavior'' may help understand the 6879 disagreement between previous estimates of the clusters' fractal 6880 dimension. 6881 C1 IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598. 6882 UNIV PITTSBURGH,DEPT PHYS & ASTRON,PITTSBURGH,PA 15260. 6883 HONG KONG POLYTECH,DEPT APPL PHYS,KOWLOON,HONG KONG. 6884 RP MANDELBROT, BB, YALE UNIV,DEPT MATH,BOX 208283,NEW HAVEN,CT 06520. 6885 CR LAM CH, IN PRESS 6886 MANDELBROT BB, 1982, FRACTAL GEOMETRY NAT 6887 MANDELBROT BB, 1992, PHYSICA A, V191, P95 6888 MEAKIN P, 1985, PHYS REV LETT, V54, P2053 6889 MEAKIN P, 1988, PHASE TRANSITIONS CR, V12, P335 6890 OSSADNIK P, 1993, PHYSICA A, V195, P319 6891 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 6892 PLISCHKE M, 1984, PHYS REV LETT, V53, P415 6893 VICSEK T, 1989, FRACTAL GROWTH PHENO 6894 VOSS RF, 1993, FRACTALS, V1, P141 6895 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 6896 YEKUTIELI I, 1994, J PHYS A-MATH GEN, V27, P275 6897 NR 12 6898 TC 20 6899 PU EDITIONS PHYSIQUE 6900 PI LES ULIS CEDEX 6901 PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, 6902 FRANCE 6903 SN 0295-5075 6904 J9 EUROPHYS LETT 6905 JI Europhys. Lett. 6906 PD MAR 10 6907 PY 1995 6908 VL 29 6909 IS 8 6910 BP 599 6911 EP 604 6912 PG 6 6913 SC Physics, Multidisciplinary 6914 GA QN883 6915 UT ISI:A1995QN88300002 6916 ER 6917 6918 PT J 6919 AU VESPIGNANI, A 6920 ZAPPERI, S 6921 PIETRONERO, L 6922 TI RENORMALIZATION APPROACH TO THE SELF-ORGANIZED CRITICAL-BEHAVIOR OF 6923 SANDPILE MODELS 6924 SO PHYSICAL REVIEW E 6925 LA English 6926 DT Article 6927 ID DIFFUSION-LIMITED AGGREGATION; CRITICAL EXPONENTS; PHASE-TRANSITIONS; 6928 UNIVERSALITY; DYNAMICS; SYSTEMS; NOISE 6929 C1 YALE UNIV,DEPT MATH,NEW HAVEN,CT 06520. 6930 BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215. 6931 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. 6932 RP VESPIGNANI, A, UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,PIAZZALE ALDO 6933 MORO 2,I-00185 ROME,ITALY. 6934 CR BAK P, 1987, PHYS REV LETT, V59, P381 6935 BAK P, 1988, PHYS REV A, V38, P364 6936 BAK P, 1989, NATURE, V342, P780 6937 BAK P, 1993, FRACTALS DISORDERED, V2 6938 BAK P, 1993, RICERCHE ECONOMICHE, V47, P3 6939 BURKHARDT TW, 1982, REAL SPACE RENORMALI 6940 CAFIERO R, 1993, PHYS REV LETT, V70, P3939 6941 CAFIERO R, 1995, EUROPHYS LETT, V29, P111 6942 CALDARELLI G, COMMUNICATION 6943 CHRISTENSEN K, 1991, J STAT PHYS, V61, P653 6944 CHRISTENSEN K, 1992, PHYS REV A, V46, P1829 6945 CRESWICK RJ, 1992, INTRO RENORMALIZATIO 6946 DHAR D, 1989, PHYS REV LETT, V63, P1659 6947 DHAR D, 1991, PHYS REV LETT, V64, P1613 6948 DIAZGUILERA A, 1992, PHYS REV A, V45, P8551 6949 DIAZGUILERA A, 1994, EUROPHYS LETT, V26, P177 6950 ERZAN A, UNPUB 6951 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 6952 HWA T, 1989, PHYS REV LETT, V62, P1813 6953 KADANOFF LP, 1989, PHYS REV A, V39, P6524 6954 KADANOFF LP, 1990, PHYSICA A, V163, P1 6955 KADANOFF LP, 1991, PHYS TODAY, V44, P9 6956 LORETO V, UNPUB 6957 MAJUMDAR SN, 1992, PHYSICA A, V185, P129 6958 MANNA SS, 1990, J STAT PHYS, V59, P509 6959 MANNA SS, 1990, J STAT PHYS, V61, P923 6960 MANNA SS, 1991, J PHYS A, V24, L363 6961 MANNA SS, 1991, PHYSICA A, V179, P249 6962 OLAMI Z, 1992, PHYS REV LETT, V68, P1244 6963 PACZUSKI M, 1994, EUROPHYS LETT, V27, P97 6964 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 6965 PIETRONERO L, 1991, PHYS REV LETT, V66, P2336 6966 PIETRONERO L, 1991, PHYSICA A, V173, P129 6967 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 6968 SORNETTE D, 1992, J PHYS I, V2, P2065 6969 TANG C, 1988, PHYS REV LETT, V60, P2347 6970 VICSEK T, 1992, FRACTAL GROWTH PHENO 6971 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 6972 ZHANG YC, 1989, PHYS REV LETT, V63, P470 6973 NR 39 6974 TC 71 6975 PU AMERICAN PHYSICAL SOC 6976 PI COLLEGE PK 6977 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 6978 SN 1063-651X 6979 J9 PHYS REV E 6980 JI Phys. Rev. E 6981 PD MAR 6982 PY 1995 6983 VL 51 6984 IS 3 6985 PN Part A 6986 BP 1711 6987 EP 1724 6988 PG 14 6989 SC Physics, Fluids & Plasmas; Physics, Mathematical 6990 GA QP252 6991 UT ISI:A1995QP25200016 6992 ER 6993 6994 PT J 6995 AU CAFIERO, R 6996 LORETO, V 6997 PIETRONERO, L 6998 VESPIGNANI, A 6999 ZAPPERI, S 7000 TI LOCAL RIGIDITY AND SELF-ORGANIZED CRITICALITY FOR AVALANCHES 7001 SO EUROPHYSICS LETTERS 7002 LA English 7003 DT Article 7004 ID FOREST-FIRE MODEL; FRACTAL GROWTH; RELAXATION 7005 AB The general conditions for a sandpile system to evolve spontaneously 7006 into a critical state characterized by a power law distribution of 7007 avalanches or bursts are identified as: a) the existence of a 7008 stationary state with a global conservation law; b) long-range 7009 correlations in the continuum limit (i.e. Laplacian diffusive field); 7010 c) the existence of a local rigidity for the microscopic dynamics. 7011 These conditions permit a classification of the models that have been 7012 considered up to now and the identification of the local rigidity as a 7013 new basic parameter that can lead to various possible scenarios ranging 7014 continuously from SOC behaviour to standard diffusion. 7015 RP CAFIERO, R, UNIV ROMA I LA SAPIENZA,DIPARTIMENTO FIS,P A MORO 2,I-00185 7016 ROME,ITALY. 7017 CR BAK P, COMMUNICATION 7018 BAK P, 1987, PHYS REV LETT, V59, P381 7019 BAK P, 1988, PHYS REV A, V38, P364 7020 BAK P, 1990, PHYS LETT A, V147, P297 7021 BAK P, 1993, PHYS REV LETT, V71, P4083 7022 DIAZGUILERA A, 1994, EUROPHYS LETT, V26, P177 7023 DROSSEL B, 1992, PHYS REV LETT, V69, P1629 7024 ERZAN A, IN PRESS REV MOD PHY 7025 LORETO V, UNPUB PHYS REV LETT 7026 MA SK, 1976, MODERN THEORY CRITIC 7027 OLAMI Z, 1992, PHYS REV LETT, V68, P1244 7028 PARISI G, 1991, PHYSICA A, V179, P16 7029 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 7030 PIETRONERO L, 1990, PHYSICA A, V170, P81 7031 PIETRONERO L, 1991, PHYS REV LETT, V66, P2336 7032 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 7033 VICKSEK T, 1989, FRACTAL GROWTH PHENO 7034 ZHANG YC, 1987, PHYS REV LETT, V63, P470 7035 NR 18 7036 TC 18 7037 PU EDITIONS PHYSIQUE 7038 PI LES ULIS CEDEX 7039 PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, 7040 FRANCE 7041 SN 0295-5075 7042 J9 EUROPHYS LETT 7043 JI Europhys. Lett. 7044 PD JAN 10 7045 PY 1995 7046 VL 29 7047 IS 2 7048 BP 111 7049 EP 116 7050 PG 6 7051 SC Physics, Multidisciplinary 7052 GA QC369 7053 UT ISI:A1995QC36900001 7054 ER 7055 7056 PT J 7057 AU PETRI, A 7058 PAPARO, G 7059 VESPIGNANI, A 7060 ALIPPI, A 7061 COSTANTINI, M 7062 TI EXPERIMENTAL-EVIDENCE FOR CRITICAL-DYNAMICS IN MICROFRACTURING PROCESSES 7063 SO PHYSICAL REVIEW LETTERS 7064 LA English 7065 DT Article 7066 ID SELF-ORGANIZED CRITICALITY; ACOUSTIC-EMISSION; 1/F NOISE 7067 C1 UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY. 7068 UNIV ROMA LA SAPIENZA,DIPARTIMENTO ENERGET,I-00161 ROME,ITALY. 7069 RP PETRI, A, CNR,IST ACUST OM CORBINO,VIA CASSIA 1216,I-00189 ROME,ITALY. 7070 CR BAK P, 1987, PHYS REV LETT, V59, P381 7071 BAK P, 1988, PHYS REV A, V38, P364 7072 BAK P, 1989, NETURE, V342, P7800 7073 BAK P, 1993, FRACTALS DISORDERED, V2 7074 CANNELLI G, 1993, PHYS REV LETT, V70, P3923 7075 CHRISTENSEN K, 1991, J STAT PHYS, V63, P653 7076 CHRISTENSEN K, 1992, PHYS REV LETT, V68, P2417 7077 DIODATI P, 1991, PHYS REV LETT, V67, P2239 7078 GUTENBERG B, 1956, ANN GEOFIS, V9, P1 7079 HIRATA T, 1987, J GEOPHYS RES-SOLID, V92, P6215 7080 HUANG J, 1988, EARTH PLANET SC LETT, V91, P223 7081 ISHIMOTO M, 1939, B EARTHQ RES I TOKYO, V17, P443 7082 KERTESZ J, 1990, J PHYS A, V23, L433 7083 LORD AE, 1981, PHYSICAL ACOUSTICS, V15 7084 MCDONALD DKC, 1962, NOISE FLUCTUATIONS 7085 MOGI K, 1962, B EARTHQ RES I TOKIO, V40, P815 7086 MOGI K, 1962, B EARTHQ RES I TOKYO, V40, P125 7087 MOGI K, 1962, B EARTHQ RES I TOKYO, V40, P831 7088 MOGI K, 1963, B EARTHQ RES I TOKYO, V41, P595 7089 MOGI K, 1967, TECTONOPHYSICS, V5, P35 7090 OMORI F, 1894, REP EARTH INV COMM, V2, P103 7091 OMORI F, 1969, TOKUJI UTSU, V3, P129 7092 PACZUSKI M, IN PRESS 7093 PIETRONERO L, 1994, PHYS REV LETT, V72, P1690 7094 SORNETTE A, 1989, EUROPHYS LETT, V9, P197 7095 NR 25 7096 TC 99 7097 PU AMERICAN PHYSICAL SOC 7098 PI COLLEGE PK 7099 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 7100 SN 0031-9007 7101 J9 PHYS REV LETT 7102 JI Phys. Rev. Lett. 7103 PD DEC 19 7104 PY 1994 7105 VL 73 7106 IS 25 7107 BP 3423 7108 EP 3426 7109 PG 4 7110 SC Physics, Multidisciplinary 7111 GA PX387 7112 UT ISI:A1994PX38700024 7113 ER 7114 7115 PT J 7116 AU CALDARELLI, G 7117 CASTELLANO, C 7118 VESPIGNANI, A 7119 TI FRACTAL AND TOPOLOGICAL PROPERTIES OF DIRECTED FRACTURES 7120 SO PHYSICAL REVIEW E 7121 LA English 7122 DT Article 7123 ID DIFFUSION-LIMITED AGGREGATION; DIELECTRIC-BREAKDOWN; ELASTIC NETWORKS; 7124 MODEL; GROWTH 7125 AB We use the Born model for the energy of elastic networks to simulate 7126 ''directed'' fracture growth. We define directed fractures as crack 7127 patterns showing a preferential evolution direction imposed by the type 7128 of stress and boundary conditions applied. This type of fracture allows 7129 a more realistic description of some kinds of experimental cracks and 7130 presents several advantages in order to distinguish between the various 7131 growth regimes. By choosing this growth geometry it is also possible to 7132 use without ambiguity the box-counting method to obtain the fractal 7133 dimension for different subsets of the patterns and for a wide range of 7134 the internal parameters of the model. We find a continuous dependence 7135 of the fractal dimension of the whole patterns and of their backbones 7136 on the ratio between the central- and noncentral-force contributions. 7137 For the chemical distance we find a one-dimensional behavior 7138 independent of the relevant parameters, which seems to be a common 7139 feature for fractal growth processes. 7140 C1 UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY. 7141 UNIV NAPLES,DIPARTIMENTO SCI FIS,I-80125 NAPLES,ITALY. 7142 RP CALDARELLI, G, SCUOLA INT SUPER STUDI AVANZATI,VIA BEIRUT 2-4,I-34014 7143 GRIGNANO,ITALY. 7144 CR EVERTSZ C, 1990, PHYS REV A, V41, P1830 7145 FENG S, 1984, PHYS REV LETT, V52, P216 7146 HERRMANN HJ, 1990, STATISTICAL MODELS F 7147 HERRMANN HJ, 1991, PHYS SCR T, V38, P13 7148 HORVATH VK, 1991, CHAOS SOLITON FRACT, V1, P395 7149 LANDAU LD, 1960, ELASTICITY 7150 LOUIS E, 1987, EUROPHYS LETT, V3, P871 7151 MEAKIN P, 1984, J PHYS A, V17, L975 7152 MEAKIN P, 1989, J PHYS A-MATH GEN, V22, P1393 7153 NIEMEYER L, 1984, PHYS REV LETT, V52, P1033 7154 OSSADNIK P, 1993, HLRZ10L9I REP 7155 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 7156 PIETRONERO L, 1988, PHYSICA A, V151, P207 7157 SEN PN, 1977, PHYS REV B, V15, P4030 7158 VICSEK T, 1992, FRACTAL GROWTH PHENO 7159 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 7160 YAN H, 1989, EUROPHYS LETT, V10, P7 7161 NR 17 7162 TC 20 7163 PU AMERICAN PHYSICAL SOC 7164 PI COLLEGE PK 7165 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 7166 SN 1063-651X 7167 J9 PHYS REV E 7168 JI Phys. Rev. E 7169 PD APR 7170 PY 1994 7171 VL 49 7172 IS 4 7173 PN Part A 7174 BP 2673 7175 EP 2679 7176 PG 7 7177 SC Physics, Fluids & Plasmas; Physics, Mathematical 7178 GA NJ379 7179 UT ISI:A1994NJ37900027 7180 ER 7181 7182 PT J 7183 AU PIETRONERO, L 7184 VESPIGNANI, A 7185 ZAPPERI, S 7186 TI RENORMALIZATION SCHEME FOR SELF-ORGANIZED CRITICALITY IN SANDPILE MODELS 7187 SO PHYSICAL REVIEW LETTERS 7188 LA English 7189 DT Article 7190 ID UNIVERSALITY 7191 AB We introduce a renormalization scheme of novel type that allows us to 7192 characterize the critical state and the scale invariant dynamics in 7193 sandpile models. The attractive fixed point clarifies the nature of 7194 self-organization in these systems. Universality classes can be 7195 identified and the critical exponents can be computed analytically. We 7196 obtain tau = 1.253 for the avalanche exponent and z = 1.234 for the 7197 dynamical exponent. These results are in good agreement with computer 7198 simulations. The method can be naturally extended to other problems 7199 with nonequilibrium stationary states. 7200 RP PIETRONERO, L, UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,PIAZZALE A MORO 7201 2,I-00185 ROME,ITALY. 7202 CR BAK P, BNL49030 REP 7203 BAK P, 1987, PHYS REV LETT, V59, P381 7204 BAK P, 1988, PHYS REV A, V38, P364 7205 BAK P, 1993, FRACTALS DISORDERED, V2 7206 CAFIERO R, 1993, PHYS REV LETT, V70, P3939 7207 CHRISTENSEN K, 1992, PHYS REV A, V46, P1829 7208 DHAR D, 1989, PHYS REV LETT, V63, P1659 7209 DHAR D, 1990, J PHYS A-MATH GEN, V23, P4333 7210 DHAR D, 1990, PHYS REV LETT, V64, P161 7211 ERZAN A, IN PRESS FIXED SCALE 7212 GRASSBERGER P, 1990, J PHYS-PARIS, V51, P1077 7213 KADANOFF LP, 1989, PHYS REV A, V39, P6524 7214 KADANOFF LP, 1990, PHYSICA A, V163, P1 7215 KADANOFF LP, 1991, PHYS TODAY, V44, P9 7216 MANNA SS, 1990, J STAT PHYS, V59, P509 7217 MANNA SS, 1990, J STAT PHYS, V61, P923 7218 MANNA SS, 1991, J PHYS A, V24, L363 7219 MANNA SS, 1991, PHYSICA A, V179, P249 7220 OLAMI Z, 1992, PHYS REV LETT, V68, P1244 7221 PACZUSKI M, IN PRESS 7222 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 7223 PIETRONERO L, 1991, PHYS REV LETT, V66, P2336 7224 PIETRONERO L, 1991, PHYSICA A, V173, P22 7225 SORNETTE D, 1992, J PHYS I, V2, P2065 7226 VESPIGNANI A, IN PRESS 7227 VICSEK T, 1992, FRACTAL GROWTH PHENO 7228 ZHANG YC, 1989, PHYS REV LETT, V63, P470 7229 NR 27 7230 TC 103 7231 PU AMERICAN PHYSICAL SOC 7232 PI COLLEGE PK 7233 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 7234 SN 0031-9007 7235 J9 PHYS REV LETT 7236 JI Phys. Rev. Lett. 7237 PD MAR 14 7238 PY 1994 7239 VL 72 7240 IS 11 7241 BP 1690 7242 EP 1693 7243 PG 4 7244 SC Physics, Multidisciplinary 7245 GA NA492 7246 UT ISI:A1994NA49200030 7247 ER 7248 7249 PT J 7250 AU DISTASIO, M 7251 PIETRONERO, L 7252 STELLA, A 7253 VESPIGNANI, A 7254 TI FIXED-SCALE TRANSFORMATION APPROACH TO LINEAR AND BRANCHED POLYMERS 7255 SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL 7256 LA English 7257 DT Article 7258 ID DIFFUSION-LIMITED AGGREGATION; FRACTAL GROWTH; PERCOLATION; 7259 RENORMALIZATION; LATTICE 7260 AB The radius exponent of two- and three-dimensional self-avoiding walks 7261 and branched polymers are computed in the fixed-scale transformation 7262 framework. The method requires the knowledge of the critical fugacity 7263 k(c), but from this non-universal parameter it is possible to compute 7264 the universal critical exponent. The results obtained are within 1% of 7265 exact or numerical values. This confirms the versatility and 7266 quantitative power of this new theoretical approach and gives the 7267 opportunity to provide a discussion of the analogies and differences 7268 between the real space renormalization group and the fixed-scale 7269 transformation method. 7270 C1 UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY. 7271 UNIV BOLOGNA,DIPARTIMENTO FIS,BOLOGNA,ITALY. 7272 RP DISTASIO, M, ISAS,SISSA,VIA BEIRUT 2,I-34100 MIRAMARE,ITALY. 7273 CR BURKHARDT TW, 1982, REAL SPACE RENORMALI 7274 DEGENNES PG, 1979, SCALING CONCEPTS POL 7275 DERRIDA B, 1985, J PHYS-PARIS, V46, P1623 7276 FAMILY F, 1980, J PHYS A, V13, L325 7277 FAMILY F, 1980, J PHYS A-MATH GEN, V13, L403 7278 FLORY PJ, 1971, PRINCIPLES POLYM CHE 7279 GUTTMANN AJ, 1978, J PHYS A, V11, P949 7280 HERRMANN HJ, 1986, GROWTH FORM 7281 LEGUILLOU JC, 1980, PHYS REV B, V21, P3976 7282 NENHUIS B, 1982, PHYS REV LETT, V49, P1062 7283 NIEMEYER L, 1984, PHYS REV LETT, V52, P1038 7284 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 7285 PIETRONERO L, 1988, PHYSICA A, V151, P207 7286 PIETRONERO L, 1990, PHYSICA A, V170, P64 7287 PIETRONERO L, 1991, NONLINEAR PHENOMENA 7288 SYKES MF, 1972, J PHYS A, V5, P653 7289 VESPIGNANI A, 1991, PHYSICA A, V173, P21 7290 VICSEK T, 1989, FRACTAL GROWTH PHENO 7291 WATTS MG, 1975, J PHYS A, V8, P61 7292 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 7293 NR 20 7294 TC 2 7295 PU IOP PUBLISHING LTD 7296 PI BRISTOL 7297 PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX 7298 SN 0305-4470 7299 J9 J PHYS-A-MATH GEN 7300 JI J. Phys. A-Math. Gen. 7301 PD JAN 21 7302 PY 1994 7303 VL 27 7304 IS 2 7305 BP 317 7306 EP 326 7307 PG 10 7308 SC Physics, Multidisciplinary; Physics, Mathematical 7309 GA MV126 7310 UT ISI:A1994MV12600016 7311 ER 7312 7313 PT J 7314 AU CAFIERO, R 7315 PIETRONERO, L 7316 VESPIGNANI, A 7317 TI PERSISTENCE OF SCREENING AND SELF-CRITICALITY IN THE SCALE-INVARIANT 7318 DYNAMICS OF DIFFUSION-LIMITED AGGREGATION 7319 SO PHYSICAL REVIEW LETTERS 7320 LA English 7321 DT Article 7322 ID RENORMALIZATION-GROUP APPROACH; FRACTAL GROWTH; ANISOTROPY; PATTERNS 7323 AB The origin of fractal properties in diffusion limited aggregation is 7324 related to the persistence of screening in the scale invariant growth 7325 regime. This effect is described by the effective noise reduction 7326 parameter S spontaneously generated by the scale invariant dynamics. 7327 The renormalization of this parameter under scale transformation shows 7328 the following: (i) The fixed point is attractive, implying the 7329 self-critical nature of the process. (ii) The fixed point value S* is 7330 of the order of unity, showing that the small scale growth rules are 7331 already close to the scale invariant ones and that screening effects 7332 persist in the asymptotic regime. 7333 RP CAFIERO, R, UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,PIAZZALE A MORO 7334 2,I-00185 ROME,ITALY. 7335 CR AMAR MB, 1991, NATO ASI SER B, V276, P345 7336 BARKER PW, 1990, PHYS REV A, V42, P6289 7337 CAFIERO R, IN PRESS 7338 DEANGELIS R, 1991, EUROPHYS LETT, V16, P417 7339 ECKMANN JP, 1989, PHYS REV A, V39, P3185 7340 ECKMANN JP, 1990, PHYS REV LETT, V65, P52 7341 KERTESZ J, 1986, J PHYS A, V19, L257 7342 MOUKARZEL C, 1992, PHYSICA A, V188, P469 7343 NAGATANI T, 1987, J PHYS A, V20, L381 7344 NAGATANI T, 1987, PHYS REV A, V36, P5812 7345 NITTMANN J, 1986, NATURE, V321, P663 7346 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 7347 PIETRONERO L, 1988, PHYSICA A, V151, P207 7348 PIETRONERO L, 1990, PHYSICA A, V170, P64 7349 PIETRONERO L, 1992, PHYSICA A, V191, P85 7350 VICSEK T, 1992, FRACTAL GROWTH PHENO 7351 WANG XR, 1989, J PHYS A, V22, L507 7352 WANG XR, 1989, PHYS REV A, V39, P5974 7353 WANG XZ, 1992, PHYS REV A, V46, P5038 7354 NR 19 7355 TC 31 7356 PU AMERICAN PHYSICAL SOC 7357 PI COLLEGE PK 7358 PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA 7359 SN 0031-9007 7360 J9 PHYS REV LETT 7361 JI Phys. Rev. Lett. 7362 PD JUN 21 7363 PY 1993 7364 VL 70 7365 IS 25 7366 BP 3939 7367 EP 3942 7368 PG 4 7369 SC Physics, Multidisciplinary 7370 GA LH554 7371 UT ISI:A1993LH55400026 7372 ER 7373 7374 PT J 7375 AU VESPIGNANI, A 7376 CAFIERO, R 7377 PIETRONERO, L 7378 TI ASYMPTOTIC SCREENING IN THE SCALE INVARIANT GROWTH RULES FOR LAPLACIAN 7379 FRACTALS 7380 SO PHYSICA A 7381 LA English 7382 DT Article 7383 ID DIFFUSION-LIMITED AGGREGATION; ANISOTROPY; PATTERNS 7384 AB A key element in the fixed scale transformation approach to fractal 7385 growth is the use of the asymptotic scale invariant dynamics of the 7386 growth process. This is a non-universal element, analogous to the 7387 critical probability or temperature in percolation or Ising problems. 7388 The essential property to generate fractal structure is the persistence 7389 of screening effects in the asymptotic regime. To investigate this 7390 problem we use a renormalization procedure in which the noise reduction 7391 parameter is the critical one. The approach is based on the growth 7392 process itself and shows a non-trivial fixed point where the screening 7393 properties are preserved. This result guarantees the existence of the 7394 asymptotic fractal structure and clearly defines the basic elements of 7395 the growth rules used in the fixed scale transformation method. 7396 RP VESPIGNANI, A, UNIV ROME LA SAPIENZA,DIPARTIMENTO FIS,P A MORO 7397 2,I-00185 ROME,ITALY. 7398 CR BARKER PW, 1990, PHYS REV A, V42, P6289 7399 CAFIERO R, 1992, PREPRINT 7400 DEANGELIS R, 1991, EUROPHYS LETT, V16, P417 7401 DISTASIO M, 1992, PREPRINT 7402 ECKMANN JP, 1989, PHYS REV A, V39, P3185 7403 ERZAN A, 1991, J PHYS A, V24, P1875 7404 KERTESZ J, 1986, J PHYS A, V19, L257 7405 MEAKIN P, 1989, PHASE TRANSITIONS CR, V11 7406 MOUKARZEL C, 1992, HLRZ1692 PREPR 7407 NIEMEYER L, 1984, PHYS REV LETT, V52, P1038 7408 NITTMANN J, 1986, NATURE, V321, P663 7409 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 7410 PIETRONERO L, 1988, PHYSICA A, V151, P207 7411 PIETRONERO L, 1990, PHYSICA A, V170, P64 7412 SELINGER RLB, 1989, PREPRINT 7413 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 7414 NR 16 7415 TC 0 7416 PU ELSEVIER SCIENCE BV 7417 PI AMSTERDAM 7418 PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS 7419 SN 0378-4371 7420 J9 PHYSICA A 7421 JI Physica A 7422 PD DEC 15 7423 PY 1992 7424 VL 191 7425 IS 1-4 7426 BP 128 7427 EP 133 7428 PG 6 7429 SC Physics, Multidisciplinary 7430 GA KF666 7431 UT ISI:A1992KF66600021 7432 ER 7433 7434 PT J 7435 AU SIDORETTI, S 7436 VESPIGNANI, A 7437 TI FIXED SCALE TRANSFORMATION APPLIED TO CLUSTER CLUSTER AGGREGATION IN 7438 2-DIMENSIONS AND 3-DIMENSIONS 7439 SO PHYSICA A 7440 LA English 7441 DT Article 7442 ID DIFFUSION-LIMITED AGGREGATION 7443 AB Recently it has been introduced a new theoretical framework named fixed 7444 scale transformation (FST), which appears particularly suitable to 7445 study the growth of fractal structures. This method allows the first 7446 study of the process of cluster-cluster aggregation (CCA). The FST 7447 approach can in fact be generalized in a natural and relatively simple 7448 way to the case of CCA. Here we present detailed results for the 7449 analytical calculation of the fractal dimension of the aggregates. For 7450 CCA in two dimensions the computed value is D = 1.39 and in three 7451 dimensions is D = 1.9, to be compared with the simulation results that 7452 are respectively D = 1.45 and D = 1.8. Furthermore the approximation 7453 scheme of the FST can be implemented in a systematic way to estimate 7454 quantitatively higher Order corrections and to study variation of the 7455 original model. This application is of particular relevance because CCA 7456 has eluded all the standard theoretical approach and in particular it 7457 cannot even be formulated from the point of view of renormalization 7458 group methods. 7459 RP SIDORETTI, S, UNIV ROME LA SAPIENZA,DIPARTIMENTO FIS,P LE A MORO 7460 2,I-00185 ROME,ITALY. 7461 CR ERNST MH, 1986, FRACTALS PHYSICS, P289 7462 ERZAN A, 1992, PHYSICA A, V185, P66 7463 KOLB M, 1983, PHYS REV LETT, V51, P1123 7464 LEYVRAZ F, 1986, GROWTH FORM, P136 7465 MEAKIN P, 1983, PHYS REV LETT, V51, P1119 7466 NIEMEYER L, 1984, PHYS REV LETT, V52, P1038 7467 PIETRONERO L, IN PRESS NONLINEAR P 7468 PIETRONERO L, PREPRINT 7469 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 7470 PIETRONERO L, 1988, PHYSICA A, V40, P5377 7471 SMOLUCHOWSKI MV, 1916, PHYS Z, V17, P585 7472 VESPIGNANI A, 1991, PHYSICA A, V173, P1 7473 VICSEK T, 1984, PHYS REV LETT, V52, P1669 7474 VICSEK T, 1985, PHYS REV A, V32, P1122 7475 VICSEK T, 1989, FRACTAL GROWTH PHENO 7476 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 7477 NR 16 7478 TC 1 7479 PU ELSEVIER SCIENCE BV 7480 PI AMSTERDAM 7481 PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS 7482 SN 0378-4371 7483 J9 PHYSICA A 7484 JI Physica A 7485 PD JUN 15 7486 PY 1992 7487 VL 185 7488 IS 1-4 7489 BP 202 7490 EP 210 7491 PG 9 7492 SC Physics, Multidisciplinary 7493 GA JC914 7494 UT ISI:A1992JC91400028 7495 ER 7496 7497 PT J 7498 AU DEANGELIS, R 7499 MARSILI, M 7500 PIETRONERO, L 7501 VESPIGNANI, A 7502 WIESMANN, HJ 7503 TI UNIVERSALITY OF GROWTH RULES IN FRACTAL GROWTH 7504 SO EUROPHYSICS LETTERS 7505 LA English 7506 DT Article 7507 ID DIFFUSION-LIMITED AGGREGATION; DIELECTRIC-BREAKDOWN MODEL 7508 AB We consider the problem of the universality of growth rules in 7509 fractal-growth models and introduce a theoretical scheme that allows us 7510 to address this question. In particular we show that growth defined 7511 per site and rules that include diagonal process renormalize 7512 asymptotically into effective growth rules of simple bond type. 7513 Therefore, we identify the general nature of the asymptotic, 7514 scale-invariant growth dynamics for coarse-grained variables. 7515 C1 ASEA BROWN BOVERI CORP RES,CH-5405 BADEN,SWITZERLAND. 7516 RP DEANGELIS, R, UNIV ROME LA SAPIENZA,DIPARTMENTO FIS,PIAZZALE A MORO 7517 2,I-00185 ROME,ITALY. 7518 CR DEANGELIS R, PREPRINT 7519 ERZAN A, 1991, J PHYS A, V24, P1875 7520 EVERTSZ C, 1990, PHYS REV A, V41, P1830 7521 MEAKIN P, 1989, FRACTALS PHYSICAL OR, P137 7522 NAGATANI T, 1987, PHYS REV A, V36, P5812 7523 NIEMEYER L, 1984, PHYS REV LETT, V52, P1033 7524 PIETRONERO L, PREPRINT 7525 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 7526 PIETRONERO L, 1988, PHYSICA A, V151, P207 7527 PIETRONERO L, 1990, PHYS REV A, V42, P7496 7528 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 7529 NR 11 7530 TC 13 7531 PU EDITIONS PHYSIQUE 7532 PI LES ULIS CEDEX 7533 PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, 7534 FRANCE 7535 SN 0295-5075 7536 J9 EUROPHYS LETT 7537 JI Europhys. Lett. 7538 PD OCT 1 7539 PY 1991 7540 VL 16 7541 IS 5 7542 BP 417 7543 EP 422 7544 PG 6 7545 SC Physics, Multidisciplinary 7546 GA GJ340 7547 UT ISI:A1991GJ34000001 7548 ER 7549 7550 PT J 7551 AU VERGASSOLA, M 7552 VESPIGNANI, A 7553 TI NONCONSERVATIVE CHARACTER OF THE INTERSECTION OF SELF-SIMILAR CASCADES 7554 SO PHYSICA A 7555 LA English 7556 DT Article 7557 ID FULLY-DEVELOPED TURBULENCE; MODEL 7558 AB When a self-similar cascade is interested, the resulting cascade 7559 process generating the intersection set is in general non-conservative, 7560 i.e. in the fragmentation process the related measure is not conserved. 7561 It is shown that the non-conservative character of a cascade 7562 invalidates the experimental analysis of the process. In particular it 7563 is possible to have self-similar cascades which do not show any fractal 7564 or multifractal behaviour when the box-counting analysis is performed. 7565 In the case of fractals the most relevant example is provided by 7566 processes having negative dimensions. With respect to multifractals, 7567 our results show that a strict interpretation of dissipation in a fully 7568 developed turbulent fluid as a result of a self-similar cascade is 7569 untenable. 7570 C1 OBSERV NICE,CNRS,F-06003 NICE,FRANCE. 7571 RP VERGASSOLA, M, UNIV ROME LA SAPIENZA,DIPARTMENTO FIS,P MORO 2,I-00185 7572 ROME,ITALY. 7573 CR BENZI R, 1984, J PHYS A-MATH GEN, V17, P3521 7574 EVERSTSZ C, 1989, THESIS U GRONINGEN 7575 FRISCH U, 1978, J FLUID MECH, V87, P719 7576 JENSEN MH, 1991, PHYS REV A, V43, P798 7577 MANDELBROT B, 1976, LECT NOTES MATH, V565, P127 7578 MANDELBROT B, 1989, FRACTALS PHYSICAL OR 7579 MANDELBROT BB, 1974, J FLUID MECH, V62, P331 7580 MANDELBROT BB, 1982, FRACTAL GEOMETRY NAT 7581 MENEVEAU C, 1987, NUCL PHYS B S, V2, P49 7582 PALADIN G, 1987, PHYS REP, V156, P147 7583 PARISI G, 1985, TURBULENCE PREDICTAB 7584 PIETRONERO L, 1987, PHYSICA A, V144, P257 7585 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 7586 PIETRONERO L, 1988, PHYSICA A, V151, P207 7587 SCHERTZER D, 1990, FRACTALS PHYSICAL OR 7588 SIEBESMA AP, 1989, THESIS U GRONINGEN 7589 NR 16 7590 TC 1 7591 PU ELSEVIER SCIENCE BV 7592 PI AMSTERDAM 7593 PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS 7594 SN 0378-4371 7595 J9 PHYSICA A 7596 JI Physica A 7597 PD JUN 1 7598 PY 1991 7599 VL 174 7600 IS 2-3 7601 BP 425 7602 EP 437 7603 PG 13 7604 SC Physics, Multidisciplinary 7605 GA FU466 7606 UT ISI:A1991FU46600013 7607 ER 7608 7609 PT J 7610 AU VESPIGNANI, A 7611 PIETRONERO, L 7612 TI FIXED SCALE TRANSFORMATION APPLIED TO DIFFUSION LIMITED AGGREGATION AND 7613 DIELECTRIC-BREAKDOWN MODEL IN 3-DIMENSIONS 7614 SO PHYSICA A 7615 LA English 7616 DT Article 7617 ID FRACTAL GROWTH 7618 AB We extend the method of the fixed scale transformation (FST) to the 7619 case of fractal growth in three dimensions and apply it to diffusion 7620 limited aggregation and to the dielectric breakdown model for different 7621 values of the parameter eta. The scheme is formally similar to the 7622 two-dimensional case with the following technical complications: (i) 7623 The basis configurations for the fine graining process are five 7624 (instead of two) and consist of 2 x 2 cells. (ii) The treatment of the 7625 fluctuations of boundary conditions is far more complex and requires 7626 new schemes of approximations. In order to test the convergency of the 7627 theoretical results we consider three different schemes of increasing 7628 complexity. For DBM in three dimensions the computed values of the 7629 fractal dimension for eta = 1, 2 and 3 result to be in very good 7630 agreement with corresponding values obtained by computer simulations. 7631 These results provide an important test for the FST method as a new 7632 theoretical tool to study irreversible fractal growth. 7633 RP VESPIGNANI, A, UNIV ROME LA SAPIENZA,DIPARTMENTO FIS,PIAZZALE A MORO 7634 2,I-00185 ROME,ITALY. 7635 CR DEANGELIS R, IN PRESS 7636 ERZAN A, 1991, IN PRESS J PHYS A 7637 EVERTSZ C, 1990, PHYS REV A, V41, P1830 7638 MEAKIN P, 1989, FRACTALS PHYSICAL OR 7639 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 7640 PIETRONERO L, 1988, PHYSICA A, V151, P207 7641 PIETRONERO L, 1990, PHYSICA A, V170, P64 7642 PIETRONERO L, 1990, PHYSICA A, V170, P81 7643 TOLMAN S, 1989, PHYSICA A, V158, P801 7644 TREMBLAY RR, 1989, PHYS REV A, V40, P5377 7645 VESPIGNANI A, 1990, PHYSICA A, V168, P723 7646 NR 11 7647 TC 11 7648 PU ELSEVIER SCIENCE BV 7649 PI AMSTERDAM 7650 PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS 7651 SN 0378-4371 7652 J9 PHYSICA A 7653 JI Physica A 7654 PD APR 15 7655 PY 1991 7656 VL 173 7657 IS 1-2 7658 BP 1 7659 EP 21 7660 PG 21 7661 SC Physics, Multidisciplinary 7662 GA FL190 7663 UT ISI:A1991FL19000001 7664 ER 7665 7666 PT J 7667 AU VESPIGNANI, A 7668 PIETRONERO, L 7669 TI EFFECT OF EMPTY CONFIGURATIONS IN THE FIXED SCALE TRANSFORMATION THEORY 7670 OF FRACTAL GROWTH 7671 SO PHYSICA A 7672 LA English 7673 DT Article 7674 RP VESPIGNANI, A, UNIV ROME LA SAPIENZA,DEPARTIMENTO FIS,PIAZZALE A MORO 7675 2,I-00185 ROME,ITALY. 7676 CR DEANGELIS R, PREPRINT 7677 MARSILI M, UNPUB PHYSICA A 7678 NIEMEYER L, 1984, PHYS REV LETT, V52, P1033 7679 PIETRONERO L, UNPUB PHYS REV LETT 7680 PIETRONERO L, 1988, PHYS REV LETT, V61, P861 7681 PIETRONERO L, 1988, PHYSICA A, V151, P207 7682 VESPIGNANI A, UNPUB 7683 WITTEN TA, 1981, PHYS REV LETT, V47, P1400 7684 NR 8 7685 TC 9 7686 PU ELSEVIER SCIENCE BV 7687 PI AMSTERDAM 7688 PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS 7689 SN 0378-4371 7690 J9 PHYSICA A 7691 JI Physica A 7692 PD OCT 1 7693 PY 1990 7694 VL 168 7695 IS 2 7696 BP 723 7697 EP 735 7698 PG 13 7699 SC Physics, Multidisciplinary 7700 GA EH667 7701 UT ISI:A1990EH66700005 7702 ER 7703 7704 EF