April 13, 2012, Ananthram Swami, Army Research Laboratory

Friday, April 13, 2012 at 3:00 PM
8 St. Mary’s Street, Room 203

Refreshments served at 2:45.

SwamiAnanthram Swami
Army Research Laboratory

Opinion Diffusion, Consensus and Radicalization

Opinion dynamics under various models of interaction have been well-studied, both for discrete opinion as well as continuous-valued opinions. We consider a class of models wherein agents may hold one of two opinions (A or B) or be undecided (hold both). In this class, an opinion change from A (B) to B (A) must be mediated through a transition to the undecided state.  We characterize the asymptotic behavior of the opinion profile when zealots of both types, possibly in different proportions, are present.  We adopt the infinite population mean-field approach, under which we show that the dynamics obey a pair of coupled quadratic equations. Our analysis reveals interesting phase transition behavior of the asymptotic opinion profile. The class of continuous-valued opinion models has been well studied under the general notion of (average) consensus.  But interactions between agents may be modulated by their current belief states. We model this trust or confidence through a non-increasing function of the opinion distance. We consider both soft interaction and hard interaction models. Our goal is to analyze the convergence properties of opinion dynamics that mark the phase transition from polarization to consensus.

Ananthram Swami received the B.Tech. degree from the Indian Institute of Technology (IIT), Bombay, the M.S. degree from Rice University, Houston, TX, and the Ph.D. degree from the University of Southern California (USC), Los Angeles, all in electrical engineering. He has held positions with Unocal Corporation, USC, CS-3 and Malgudi Systems. He was a Statistical Consultant to the California Lottery, developed HOSAT, a MATLAB-based toolbox for non-Gaussian signal processing and has held visiting faculty positions at INP, Toulouse, France. He is the Senior Research Scientist (ST) for Network Science at the U.S. Army Research Laboratory.  He is a Fellow of the IEEE and an ARL Fellow.

Hosting Professor: Venkatesh Saligrama
Student Host: Taylor Locke