HTG-GCL: Leveraging Hierarchical Topological Granularity from Cellular Complexes for Graph Contrastive Learning
Existing graph contrastive learning (GCL) methods struggle to identify task-relevant topological structures and fail to adaptively learn multi-granular topological representations required by downstream tasks. To address this, we propose HTG-GCL—a hierarchical topological graph GCL framework. First, we introduce the novel concept of *topological granularity* and construct multi-scale contrastive graph views grounded in cycle-based cell complexes. Second, we design a multi-granularity decoupled contrastive mechanism that jointly models coarse-grained global structure and fine-grained local patterns. Third, we propose an uncertainty-aware granularity weighting strategy to dynamically fuse hierarchical topological information. Extensive experiments on multiple benchmark datasets demonstrate that HTG-GCL consistently outperforms state-of-the-art GCL methods, validating its effectiveness in enhancing representation discriminability, task adaptability, and robustness.