Original title: Edge-Girth as a Structural Edge Feature for Graph Neural Networks
Lilian Marey, Charlotte Laclau · September 2026
Graph neural networks, or computer models that process network structures, struggle to tell certain distinct graphs apart. To fix this, researchers usually add counts of small shapes, like triangles. But this forces them to pick the shape sizes ahead of time without knowing the data. The authors studied a different method called edge-girth. For each connection, it finds the length of the shortest loop passing through it and counts how many such shortest loops exist. This captures loops of any size using one simple search per connection. When tested on a molecule dataset called ZINC-12k, their model cut the prediction error to a factor three below the nearest competitor. It matched a method that counts loops up to length eight while using fewer channels. However, if every connection in a graph shares identical loop lengths and counts, the feature becomes uniform, leaving the model unable to separate those graphs.
Imagine you're trying to understand a city's road network by looking at shortcuts that form loops. If you only count loops of exactly three blocks, you might miss longer loops that affect traffic flow. In this paper, instead of choosing a loop size in advance, the system measures the shortest loop through each road and how many such loops exist, so it can account for loops of any length.
This helps AI models that predict properties of molecules, like in drug discovery. By avoiding arbitrary choices about which cycle sizes to count, it can make more accurate predictions from graph data.
The descriptor becomes ineffective on graphs where all edges have the same number of shortest cycles of the same length, causing the model to revert to basic 1-WL performance. It also requires computation of per-edge features via breadth-first search, which may add overhead.
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Edge-Girth as a Structural Edge Feature for Graph Neural Networks — Lilian Marey, Charlotte Laclau
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.