DOI: 10.1140/epjb/e2004-00123-0 THE EUROPEAN PHYSICAL JOURNAL B Self-contained algorithms to detect communities in networks

Abstract. The investigation of community structures in networks is an important issue in many domains and disciplines. In this paper we present a new class of local and fast algorithms which incorporate a quantitative definition of community. In this way the algorithms for the identification of the community structure become fully self-contained and one does not need additional non-topological information in order to evaluate the accuracy of the results. The new algorithms are tested on artificial and real-world graphs. In particular we show how the new algorithms apply to a network of scientific collaborations both in the unweighted and in the weighted version. Moreover we discuss the applicability of these algorithms to other non-social networks and we present preliminary results about the detection of community structures in networks of interacting proteins. PACS. 89.75.Hc Networks and genealogical trees – 87.23.Ge Dynamics of social systems – 87.90.+y Other topics in biological and medical physics