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Can we ease the Injectivity Bottleneck on Lorentzian Manifolds for Graph Neural Networks?

Machine Learning 2025-07-21 v5 Artificial Intelligence

Abstract

While hyperbolic GNNs show promise for hierarchical data, they often have limited discriminative power compared to Euclidean counterparts or the WL test, due to non-injective aggregation. To address this expressivity gap, we propose the Lorentzian Graph Isomorphic Network (LGIN), a novel HGNN designed for enhanced discrimination within the Lorentzian model. LGIN introduces a new update rule that preserves the Lorentzian metric while effectively capturing richer structural information. This marks a significant step towards more expressive GNNs on Riemannian manifolds. Extensive evaluations across nine benchmark datasets demonstrate LGIN's superior performance, consistently outperforming or matching state-of-the-art hyperbolic and Euclidean baselines, showcasing its ability to capture complex graph structures. LGIN is the first to adapt principles of powerful, highly discriminative GNN architectures to a Riemannian manifold. The code for our paper can be found at https://github.com/Deceptrax123/LGIN

Keywords

Cite

@article{arxiv.2504.00142,
  title  = {Can we ease the Injectivity Bottleneck on Lorentzian Manifolds for Graph Neural Networks?},
  author = {Srinitish Srinivasan and Omkumar CU},
  journal= {arXiv preprint arXiv:2504.00142},
  year   = {2025}
}

Comments

Accepted at ACM SIGMOD/PODS 2025 GRADES NDA Workshop (Non-Archival) Poster: https://drive.google.com/file/d/1hjUqbIWrjhZ1YTFDGFK9hxGYiz9xYLSC/view?usp=drive_link