English

A short proof that $\chi$ can be bounded $\epsilon$ away from $\Delta+1$ towards $\omega$

Discrete Mathematics 2012-11-08 v1 Combinatorics

Abstract

In 1998 the second author proved that there is an ϵ>0\epsilon>0 such that every graph satisfies χ(1ϵ)(Δ+1)+ϵω\chi \leq \lceil (1-\epsilon)(\Delta+1)+\epsilon\omega\rceil. The first author recently proved that any graph satisfying ω>23(Δ+1)\omega > \frac 23(\Delta+1) contains a stable set intersecting every maximum clique. In this note we exploit the latter result to give a much shorter, simpler proof of the former. We include, as a certificate of simplicity, an appendix that proves all intermediate results with the exception of Hall's Theorem, Brooks' Theorem, the Lov\'asz Local Lemma, and Talagrand's Inequality.

Keywords

Cite

@article{arxiv.1211.1410,
  title  = {A short proof that $\chi$ can be bounded $\epsilon$ away from $\Delta+1$ towards $\omega$},
  author = {Andrew D. King and Bruce A. Reed},
  journal= {arXiv preprint arXiv:1211.1410},
  year   = {2012}
}

Comments

10 pages. arXiv admin note: text overlap with arXiv:0911.1741