English

A superlocal version of Reed's Conjecture

Discrete Mathematics 2014-11-18 v2 Combinatorics

Abstract

Reed's well-known ω\omega, Δ\Delta, χ\chi conjecture proposes that every graph satisfies χ12(Δ+1+ω)\chi \leq \lceil \frac 12(\Delta+1+\omega)\rceil. The second author formulated a {\em local strengthening} of this conjecture that considers a bound supplied by the neighbourhood of a single vertex. Following the idea that the chromatic number cannot be greatly affected by any particular stable set of vertices, we propose a further strengthening that considers a bound supplied by the neighbourhoods of two adjacent vertices. We provide some fundamental evidence in support, namely that the stronger bound holds in the fractional relaxation and holds for both quasi-line graphs and graphs with stability number two. We also conjecture that in the fractional version, we can push the locality even further.

Keywords

Cite

@article{arxiv.1208.5188,
  title  = {A superlocal version of Reed's Conjecture},
  author = {Katherine Edwards and Andrew D. King},
  journal= {arXiv preprint arXiv:1208.5188},
  year   = {2014}
}

Comments

17 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1109.2112

R2 v1 2026-06-21T21:55:20.443Z