A Theoretical Formulation of Many-body Message Passing Neural Networks
Jiatong Han
TL;DR
The paper introduces Many-Body MPNN, a theoretical framework that extends traditional message passing to higher-order interactions by using motif-based, localized spectral filters weighted by edge Ricci curvatures. It establishes permutation invariance, derives sensitivity and energy bounds, and proves scalability to deeper and wider networks. Empirical results on synthetic energy regression and heterophilic graph classification show that the approach achieves high Dirichlet energy growth and favorable performance, while acknowledging computational trade-offs compared to two-body baselines. The work provides a principled, energy-aware perspective on graph representation learning and suggests directions toward learnable embeddings and broader applicability in complex graph topologies.
Abstract
We present many-body Message Passing Neural Network (MPNN) framework that models higher-order node interactions ($\ge 2$ nodes). We model higher-order terms as tree-shaped motifs, comprising a central node with its neighborhood, and apply localized spectral filters on motif Laplacian, weighted by global edge Ricci curvatures. We prove our formulation is invariant to neighbor node permutation, derive its sensitivity bound, and bound the range of learned graph potential. We run regression on graph energies to demonstrate that it scales well with deeper and wider network topology, and run classification on synthetic graph datasets with heterophily and show its consistently high Dirichlet energy growth. We open-source our code at https://github.com/JThh/Many-Body-MPNN.
