苹果淫院

Virtual Informal Systems Seminar (VISS)
Centre for Intelligent Machines (CIM) and Groupe d'Etudes et de Recherche en Analyse des Decisions (GERAD)

惭别别迟颈苍驳听滨顿:听845听1388听1004
笔补蝉蝉肠辞诲别:听痴滨厂厂

Speaker: Giacomo Como, Professor, Department of Mathematical Sciences, Politecnico di Torino

Abstract:
We study a network formation game where n players, identified with the nodes of a directed graph to be formed, choose where to wire their outgoing links in order to maximize their PageRank centrality. Specifically, the action of every player i consists in the wiring of a predetermined number d(i) of directed out-links, and her utility is her own PageRank centrality in the network resulting from the actions of all players. We show that this is a potential game and that the best response correspondence always exhibits a local structure in that it is never convenient for a node i to link to other nodes that are at incoming distance more than d(i) from her. We then study the equilibria of this game determining necessary conditions for a graph to be a (strict, recurrent) Nash equilibrium. Moreover, in the homogeneous case, where players all have the same number d of out-links, we characterize the structure of the potential maximizing equilibria and, in the special cases d=1 and d=2, we provide a complete classification of the set of (strict, recurrent) 听Nash equilibria. Our analysis shows in particular that the considered formation mechanism leads to the emergence of undirected and disconnected or loosely connected networks. This is a joint work with Costanza Catalano, Maria Castaldo, and Fabio Fagnani.

Biography:
Giacomo Como is 听a 听Professor at 听the Department 听of 听Mathematical 听Sciences, Politecnico di Torino, Italy. He is also a Senior Lecturer at the Automatic Control Department, Lund University, Sweden. He received the B.Sc., M.S., and Ph.D. degrees in Applied Mathematics 听from 听Politecnico 听di 听Torino, 听in 听2002, 听2004, and 2008, respectively. He was a Visiting Assistant in 听Research at Yale 听University in 2006--2007 and a Postdoctoral Associate at 听the 听Laboratory 听for 听Information 听and 听Decision 听Systems, 听Massachusetts 听Institute of Technology, from 2008 to 2011. He 听is 听recipient 听of 听the 2015 听George S. Axelby 听Outstanding Paper Award. 听His 听research interests 听are in 听dynamics, 听information, 听and 听control 听in 听network 听systems 听with 听applications to 听cyber-physical 听systems, 听infrastructure 听networks, 听and 听social and economic networks.
听