Time varying networks and the weakness of strong ties

M. Karsai, N. Perra, A. Vespignani
Scientific Reports
4:4001, (2014)
February 10, 2014

Abstract

In most social and  information systems the activity of agents generates rapidly evolving  time-varying networks. The temporal variation in networks' connectivity  patterns and the ongoing dynamic processes are usually coupled in ways that  still challenge our mathematical or computational modelling. Here we analyse  a mobile call dataset and find a simple statistical law that characterize the  temporal evolution of users' egocentric networks. We encode this observation  in a reinforcement process defining a time-varying network model that  exhibits the emergence of strong and weak ties. We study the effect of  time-varying and heterogeneous interactions on the classic rumour spreading  model in both synthetic, and real-world networks. We observe that strong ties  severely inhibit information diffusion by confining the spreading process  among agents with recurrent communication patterns. This provides the  counterintuitive evidence that strong ties may have a negative role in the  spreading of information across networks.