GCLS$^2$: Towards Efficient Community Detection using Graph Contrastive Learning with Structure Semantics

Due to powerful ability to learn representations from unlabeled graphs, graph contrastive learning (GCL) has shown excellent performance in community detection tasks. Existing GCL-based methods on the community detection usually focused on learning attribute representations of individual nodes, which, however, ignores structure semantics of communities (e.g., nodes in the same community should be close to each other). Therefore, in this paper, we will consider the semantics of community structures for the community detection, and propose an effective framework of graph contrastive learning under structure semantics (GCLS$^2$) for detecting communities. To seamlessly integrate interior dense and exterior sparse characteristics of communities with our contrastive learning strategy, we employ classic community structures to extract high-level structural views and design a structure semantic expression module to augment the original structural feature representation. Moreover, we formulate the structure contrastive loss to optimize the feature representation of nodes, which can better capture the topology of communities. Extensive experiments have been conducted on various real-world graph datasets and confirmed that GCLS$^2$ outperforms eight state-of-the-art methods, in terms of the accuracy and modularity of the detected communities.