Distributed Community Detection in Large Networks
Sheng Zhang, Rui Song, Wenbin Lu, Ji Zhu.
Year: 2023, Volume: 24, Issue: 401, Pages: 1−28
Abstract
Community detection for large networks poses challenges due to the high computational cost as well as heterogeneous community structures. In this paper, we consider widely existing real-world networks with “grouped communities” (or “the group structure”), where nodes within grouped communities are densely connected and nodes across grouped communities are relatively loosely connected. We propose a two-step community detection approach for such networks. Firstly, we leverage modularity optimization methods to partition the network into groups, where between-group connectivity is low. Secondly, we employ the stochastic block model (SBM) or degree-corrected SBM (DCSBM) to further partition the groups into communities, allowing for varying levels of between-community connectivity. By incorporating this two-step structure, we introduce a novel divide-and-conquer algorithm that asymptotically recovers both the group structure and the community structure. Numerical studies confirm that our approach significantly reduces computational costs while achieving competitive performance. This framework provides a comprehensive solution for detecting community structures in networks with grouped communities, offering a valuable tool for various applications.