Dual-Kernel Graph Community Contrastive Learning
Xiang Chen, Kun Yue, Wenjie Liu, Zhenyu Zhang, Liang Duan
TL;DR
This work tackles the scalability and latency challenges of graph contrastive learning on large graphs by introducing Dual-Kernel Graph Community Contrastive Learning (DKGCCL). It preserves node-level detail while exploiting community structure through bi-level features and MKL-based dual kernels, achieving linear-time training and reduced inference cost via a decoupled GNN and distillation to a lightweight MLP. Theoretical analyses show the dual-kernel GCCL loss can approximate multi-hop diffusion-based contrastive objectives and that the distillation objective increases mutual information with $K$-hop patterns, supporting robust downstream performance. Empirically, DKGCCL delivers state-of-the-art or competitive results across 16 real-world datasets, with strong scalability, linear inference, and substantial speedups on large graphs, validating its practical impact for large-scale graph representation learning.
Abstract
Graph Contrastive Learning (GCL) has emerged as a powerful paradigm for training Graph Neural Networks (GNNs) in the absence of task-specific labels. However, its scalability on large-scale graphs is hindered by the intensive message passing mechanism of GNN and the quadratic computational complexity of contrastive loss over positive and negative node pairs. To address these issues, we propose an efficient GCL framework that transforms the input graph into a compact network of interconnected node sets while preserving structural information across communities. We firstly introduce a kernelized graph community contrastive loss with linear complexity, enabling effective information transfer among node sets to capture hierarchical structural information of the graph. We then incorporate a knowledge distillation technique into the decoupled GNN architecture to accelerate inference while maintaining strong generalization performance. Extensive experiments on sixteen real-world datasets of varying scales demonstrate that our method outperforms state-of-the-art GCL baselines in both effectiveness and scalability.
