A weighted cycle-localization inequality
Abstract
In 1959, Erd\H{o}s and Gallai showed that every -connected graph contains a cycle of length at least . This result was subsequently extended to weighted graphs by Bondy and Fan in 1991. A natural local variant of this problem arises by considering, for each edge , the quantity , defined as the length of the longest cycle in containing (with if is a bridge). Zhao and Zhang recently proved that for every graph on vertices satisfies In this note, we establish a weighted generalization of this inequality. For a weighted graph with positive edge weights, let denote the maximum weight of a cycle containing (setting if is a bridge). We prove that Our result can be viewed as a weighted local analogue of the Bondy-Fan theorem, thereby establishing a correspondence between the global and local perspectives. Furthermore, we present a broad class of graphs attaining equality and derive necessary conditions for equality.
Keywords
Cite
@article{arxiv.2603.18536,
title = {A weighted cycle-localization inequality},
author = {Jiangdong Ai and Bin Chen and Ming Chen and Tianxiao Zhao},
journal= {arXiv preprint arXiv:2603.18536},
year = {2026}
}