Archiviertes Physik-Kolloquium:

20. Nov. 2014, 16:00 Uhr, Gebäude NW1, Raum H3

Vorstellung des Habil.-Themas: Large-scale structure in networks: From modules to hierarchies, and their evolution

Dr. Tiago de Paula Peixoto, Univ. Bremen, ITP

Networks form the backbones of a wide variety of complex systems, ranging from food webs, gene regulation and social networks to transportation networks and the internet. Due to the sheer size and complexity of many of theses systems, it remains an open challenge to formulate general descriptions of their large-scale structures, as well as to connect their structural properties with their function and dynamics, and finally to identify plausible reasons for their evolution. I will describe how generative models of network structure can be used as a tractable way to connect all these points. In particular, I will show how a general class of models that encapsulates the multilevel structure of network systems can be constructed, which allows for the principled and efficient high-resolution identification of modules and hierarchies from empirical systems. I will then show how such generative models can be used to investigate the structural and dynamical robustness of networks --- i.e. the ability to sustain function despite damage, attacks or stochastic fluctuations --- and propose a general mechanism for the emergence of large-scale structural patterns resulting from the optimization towards robustness. Throughout the talk I will illustrate the application of the methods with many empirical networks such as the internet at the autonomous systems level, the global airport network, the network of actors and films, social networks, citations among websites, co-occurrence of disease-causing genes and others.