English

On critical graphs for the chromatic edge-stability number

Combinatorics 2021-12-28 v1

Abstract

The {\em chromatic edge-stability number} esχ(G)es_{\chi}(G) of a graph GG is the minimum number of edges whose removal results in a spanning subgraph with the chromatic number smaller than that of GG. A graph GG is called {\em (3,2)(3,2)-critical} if χ(G)=3\chi(G)=3, esχ(G)=2es_{\chi}(G)=2 and for any edge eE(G)e\in E(G), esχ(Ge)<esχ(G)es_{\chi}(G-e)<es_{\chi}(G). In this paper, we characterize (3,2)(3,2)-critical graphs which contain at least five odd cycles. This answers a question proposed by Bre\v{s}ar, Klav\v{z}ar and Movarraei in [Critical graphs for the chromatic edge-stability number, {\it Discrete Math.} {\bf 343}(2020) 111845].

Keywords

Cite

@article{arxiv.2112.13387,
  title  = {On critical graphs for the chromatic edge-stability number},
  author = {Hui Lei and Xiaopan Lian and Xianhao Meng and Yongtang Shi and Yiqiao Wang},
  journal= {arXiv preprint arXiv:2112.13387},
  year   = {2021}
}

Comments

12 pages, 2 figures

R2 v1 2026-06-24T08:31:53.426Z