Demystifying Topological Message-Passing with Relational Structures: A Case Study on Oversquashing in Simplicial Message-Passing
Diaaeldin Taha, James Chapman, Marzieh Eidi, Karel Devriendt, Guido Mont\'ufar

TL;DR
This paper introduces a unifying axiomatic framework for topological message-passing that extends graph methods to higher-order structures, addressing oversquashing issues in topological deep learning.
Contribution
It provides a theoretical foundation connecting graph and topological message-passing, enabling analysis and mitigation of oversquashing in simplicial networks.
Findings
Framework extends graph algorithms to higher-order complexes
Theoretical insights into oversquashing phenomena
Empirical validation on simplicial networks
Abstract
Topological deep learning (TDL) has emerged as a powerful tool for modeling higher-order interactions in relational data. However, phenomena such as oversquashing in topological message-passing remain understudied and lack theoretical analysis. We propose a unifying axiomatic framework that bridges graph and topological message-passing by viewing simplicial and cellular complexes and their message-passing schemes through the lens of relational structures. This approach extends graph-theoretic results and algorithms to higher-order structures, facilitating the analysis and mitigation of oversquashing in topological message-passing networks. Through theoretical analysis and empirical studies on simplicial networks, we demonstrate the potential of this framework to advance TDL.
Peer Reviews
Decision·ICLR 2025 Poster
- The paper is well written and easy to follow. - Relational structures seem to provide a general unified framework that includes not only simplicial message passing but also other higher order structures. - Propositions and theorem are well defined and proofs are mathematically sound.
- The experimental settings where the combination of lifting and rewiring leads to performance improvements seems to be limited.
- Strong theoretical contribution, establishing connections between different classes of GNNs. - Theoretical machinery for understanding over squashing and other phenomena in relational and topological GNNs - New rewiring heuristics for relational and topological GNNs
- Missing discussion of the computational complexity of rewiring - Weak experimental results due to very limited set of problems the approach was evaluated with
1. The paper successfully extends key results on graph oversquashing to topological domains, providing a comprehensive theoretical foundation for this adaptation. 2. The paper tackles questions that have been of interest to the TDL community, as highlighted in the recent position paper [1]. [1] Theodore Papamarkou, Tolga Birdal, Michael M Bronstein, Gunnar E Carlsson, Justin Curry, Yue Gao, Mustafa Hajij, Roland Kwitt, Pietro Lio, Paolo Di Lorenzo, et al. Position: Topological deep learning is
1. The novelty of the paper is somewhat limited. It reduces simplicial complexes to an "influence graph" and then re-derives several previously established results on graph oversquashing. The observation that simplicial complexes can be encoded as graphs has been explored in prior work e.g. [1,2,4] (which i would quote if not quoted already), and many of the paper’s results on oversquashing closely mirror existing studies. 2. An important question regarding oversquashing and TDL is understandi
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Taxonomy
TopicsTopological and Geometric Data Analysis · Advanced Graph Neural Networks · Bioinformatics and Genomic Networks
