On the Chromatic Number of H-Free Graphs of Large Minimum Degree

Document Type

Article

Publication Date

9-1-2011

Department

Mathematics

School

Mathematics and Natural Sciences

Abstract

The problem of determining the chromatic number of H-free graphs has been well studied, with particular attention to K r -free graphs with large minimum degree. Recent progress has been made for triangle-free graphs on n vertices with minimum degree larger than n/3. In this paper, we determine the family of r-colorable graphs ℋr such that if H ∈ ℋr, there exists a constant C < (r − 2)/(r − 1) such that any H-free graph G on n vertices with δ(G) > Cn has chromatic number bounded above by a function dependent only on H and C. A value of C < (r − 2)/(r − 1) is given for every H ∈ ℋr, with particular attention to the case when χ(H) = 3.

Publication Title

Graphs and Combinatorics

Volume

27

Issue

5

First Page

741

Last Page

754

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