Jianxi Gao, Shanghai Jiao Tong University and Boston University

2012.02.22 10:30-11:30

520 Pao Yue-Kong Library

Complex networks appear in almost every aspect of science and technology. Nearly all network results have been obtained by analyzing isolated networks, but many real-world networks do in fact interact with and depend on other networks. Very recently an analytical framework for studying the percolation properties of interacting networks has been developed. Here we review the analytical framework and the results for connectivity properties for a ``network of networks’’ (NON) formed by interdependent random networks. The percolation properties of a network of networks differ greatly from those of isolated networks. In particular, networks with broad degree distributions, such as scale free networks, that are robust when analyzed as isolated networks, become vulnerable in a NON. Moreover, in a NON, cascading failures appear due to failure of dependent nodes in other networks. When there is strong interdependent coupling between the networks, the percolation transition is discontinuous (a first-order transition), unlike the well-known continuous second-order transition in single isolated networks. These results will likely be useful in a wide range of disciplines, since no networks is completely independent of other networks.

Jianxi Gao is a PH.D candidate student in Automation department in SJTU from 2008, and is a research fellow in Physics department in Boston University. He works with H. E. Stanley from Boston University and Shlomo Havlin from Bar-Ilan University. Jianxi Gao studies the robustness of complex network and collaborative control theory. He has focused primarily on the percolation on network of interdependent networks and the optimum synchronization on self-propelled agent systems. He develops a general analytical framework for studying percolation of n interdependent networks and illustrate the analytical solutions for many distinct examples. Jianxi Gao proposes a system of iterative equations somewhat analogous to Kirchhoff equations for the resistor network in the field of percolation on interdependent networks, which shows his intelligent in finding the new percolation law in complex networks. He has one paper published in Nature Physics (IF>18), one paper published in Physical Review Letters (IF>7), and 4 papers in Physical Review E (IF>2). He was invited to several conferences such as “EU-China workshop on Complexity Science” in Switzerland (2011) and “ APS March Meeting” in Boston (2012). He is the referee of several journals, such as: Europhysics Letter, New Journal of Physics, Physica A, and International Journal of Control etc..