Message Passing on the Edge: Towards Scalable and Expressive GNNs
Pablo Barceló, Fabian Jogl, Alexander Kozachinskiy, Matthias Lanzinger, Stefan Neumann, Cristóbal Rojas
TL;DR
This work introduces EB-1WL, an edge-based refinement test, and EB-GNN, an edge-centric GNN, to bridge the gap between the expressive power of higher-order WL tests and the practical efficiency of 1WL-based methods. EB-1WL achieves strictly greater expressivity than 1-WL/NC-1WL while maintaining near-linear time per iteration on sparse graphs, supported by a CFOC^3 logical characterization and a lower bound via homomorphism counts from chordal graphs of treewidth 2. EB-GNN exactly matches the expressive power of EB-1WL and demonstrates strong empirical performance across synthetic benchmarks, molecular datasets, and large cybersecurity graphs, often outperforming standard MPNNs and approaching task-specific models with substantially better efficiency. The results establish EB-GNN as a scalable, expressive general-purpose architecture for graph learning, with practical implications for large-scale real-world graphs where higher-order tests are typically prohibitive.
Abstract
We propose EB-1WL, an edge-based color-refinement test, and a corresponding GNN architecture, EB-GNN. Our architecture is inspired by a classic triangle counting algorithm by Chiba and Nishizeki, and explicitly uses triangles during message passing. We achieve the following results: (1)~EB-1WL is significantly more expressive than 1-WL. Further, we provide a complete logical characterization of EB-1WL based on first-order logic, and matching distinguishability results based on homomorphism counting. (2)~In an important distinction from previous proposals for more expressive GNN architectures, EB-1WL and EB-GNN require near-linear time and memory on practical graph learning tasks. (3)~Empirically, we show that EB-GNN is a highly-efficient general-purpose architecture: It substantially outperforms simple MPNNs, and remains competitive with task-specialized GNNs while being significantly more computationally efficient.
