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arXiv · 2412.18480

Diameter bounds for distance-regular graphs via long-scale Ollivier Ricci curvature

Kaizhe Chen·Shiping Liu
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Abstract

In this paper, we derive new sharp diameter bounds for distance regular graphs, which better answer a problem raised by Neumaier and Penji\' c in many cases. Our proof is built upon a relation between the diameter and long-scale Ollivier Ricci curvature of a graph, which can be considered as an improvement of the discrete Bonnet-Myers theorem. Our method further leads to significant improvements of existing diameter bounds for amply regular graphs and $(s,c,a,k)$-graphs.

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Kaizhe Chen, Shiping Liu. 2025-08-29. Diameter bounds for distance-regular graphs via long-scale Ollivier Ricci curvature. https://arxiv.org/abs/2412.18480

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