Title: Complex Networks in Nature
Speaker: Luis Amaral
Speaker Info: Northwestern
Brief Description:
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Abstract:
An important but much over-looked aspect in the modeling of biological, technological and social systems is the structure of the interaction networks connecting the units comprising the system. Here, I will review some recent developments in our understanding of complex networks in these areas. In particular I will demonstrate how the ``small-world'' phenomenon occurs and why it is so ubiquitous ["Small- world networks: Evidence for a crossover picture", Phys. Rev. Lett. 82, 3180 (1999)]. I will also present evidence for the possibility to classify small-world networks according to their degree distribution--- i.e., the distribution of number of connections of the units comprising the system---and suggest mechanisms for the appearance of such classes ["Classes of small-world networks", Proc. Nat. Acad. Sci. USA 97, 11149- 11152 (2000); ``The web of human sexual contacts'', Nature 411, 907 (2001)]. In the rest of my talk I discuss some of my work applying these concepts to a number of different systems including food webs, conformation spaces, etc ["Robust patterns in food-web structure", Phys. Rev. Lett. 88, 228102 (2002); "Small-world networks and the conformation space of a short lattice polymer chain", Europhys. Lett. 55, 594-600 (2001)].Date: Friday, November 22, 2002