English

The chromatic number of ($P_{5}, K_{5}-e$)-free graphs

Combinatorics 2023-04-11 v2

Abstract

Let GG be a graph. We use χ(G)\chi(G) and ω(G)\omega(G) to denote the chromatic number and clique number of GG respectively. A P5P_5 is a path on 5 vertices. A family of graphs G\mathcal{G} is said to be {\itχ\chi-bounded} if there exists some function ff such that χ(G)f(ω(G))\chi(G)\leq f(\omega(G)) for every GGG\in\mathcal{G}. In this paper, we show that the family of (P5,K5e)(P_5, K_5-e)-free graphs is χ\chi-bounded by a linear function: χ(G)max{13,ω(G)+1}\chi(G)\leq \max\{13,\omega(G)+1\}.

Keywords

Cite

@article{arxiv.2210.04682,
  title  = {The chromatic number of ($P_{5}, K_{5}-e$)-free graphs},
  author = {Yian Xu},
  journal= {arXiv preprint arXiv:2210.04682},
  year   = {2023}
}

Comments

This paper needs to be rewrote and reorganized. The last section might not be fully correct, it needs some further check