Title: The Small Community Phenomena in Networks

Speaker: Pan Peng

Time: 3:00pm, April 28th (Thursday), 2011.

Venue: Lecture Room, Level 3, Building No. 5, State Key Laboratory of Computer Science, Institute of Software, Chinese Academy of Sciences

Abstract:

Community (or cluster), which is usually thought of a subset of nodes that vertices in the set are well connected with other vertices in it and have relatively less connections with vertices outside of the set, has a wide range of applications in network science.  Traditional research mainly focuses on detecting and/or testing the clusters.

We propose a new definition of community and a novel way to study community structure, with which we are able to investigate mathematical network models to test whether they have the small community phenomenon or not, i.e., whether every vertex in the network belongs to some small community. We examine various models and establish both positive and negative results: we show that in some models small community phenomenon exists while in some other models it does not.

We also propose several geometric models of network which simultaneously have some nice global properties, that the small diameter property, the small community phenomenon and the power law degree distribution.

Joint work with Prof. Angsheng Li.

Bibliography:

Pan Peng is a fourth-year Ph.D candidate at State Key Laboratory of Computer Science, Institute of Software, Chinese Academy of Sciences. His main research interest lies in the theory of network science.