Depth-Adaptive Graph Neural Networks via Learnable Bakry-'Emery Curvature
Asela Hevapathige, Ahad N. Zehmakan, Qing Wang
TL;DR
The paper tackles the challenge of leveraging geometric graph properties to enhance GNNs by introducing a learnable Bakry-Émery curvature estimator and a depth-adaptive mechanism that assigns per-vertex message-passing depth based on curvature. By connecting curvature to diffusion dynamics, the authors establish a theoretical link to feature distinctiveness and provide a scalable learning framework that jointly optimizes curvature estimation and task performance with a curvature-guided loss. Empirically, the approach yields consistent improvements across vertex and graph tasks on a wide range of datasets, while reducing oversmoothing and improving stability. The work offers a principled, diffusion-aware means to allocate computation where it benefits learning most, potentially impacting a broad set of graph-based applications.
Abstract
Graph Neural Networks (GNNs) have demonstrated strong representation learning capabilities for graph-based tasks. Recent advances on GNNs leverage geometric properties, such as curvature, to enhance its representation capabilities by modeling complex connectivity patterns and information flow within graphs. However, most existing approaches focus solely on discrete graph topology, overlooking diffusion dynamics and task-specific dependencies essential for effective learning. To address this, we propose integrating Bakry-Émery curvature, which captures both structural and task-driven aspects of information propagation. We develop an efficient, learnable approximation strategy, making curvature computation scalable for large graphs. Furthermore, we introduce an adaptive depth mechanism that dynamically adjusts message-passing layers per vertex based on its curvature, ensuring efficient propagation. Our theoretical analysis establishes a link between curvature and feature distinctiveness, showing that high-curvature vertices require fewer layers, while low-curvature ones benefit from deeper propagation. Extensive experiments on benchmark datasets validate the effectiveness of our approach, showing consistent performance improvements across diverse graph learning tasks.
