Title
On the average degree of edge chromatic critical graphs II
Abstract
In the study of graph edge coloring for simple graphs, a graph G is called Δ-critical if Δ(G)=Δ, χ′(G)=Δ(G)+1 and χ′(H)<χ′(G) for every proper subgraph H of G. In this paper, we prove a new adjacency result of critical graphs which allows us to control the degree of vertices with distance four. Combining this result with a previous theorem proved by the authors, we show that for every ϵ>0, if G is a Δ-critical graph with order n, then the average degree d‾(G)≥(1−ϵ)Δ and the independence number α(G)≤(12+ϵ)n provided Δ is sufficiently large. This shows that, for a Δ-critical graph G, d‾(G)≥Δ−o(Δ) and α(G)≤(1/2+o(1))n as Δ→∞.
Year
DOI
Venue
2020
10.1016/j.jctb.2020.07.007
Journal of Combinatorial Theory, Series B
Keywords
DocType
Volume
Chromatic index,Δ-critical graph,Average degree,Independence number
Journal
145
ISSN
Citations 
PageRank 
0095-8956
0
0.34
References 
Authors
0
2
Name
Order
Citations
PageRank
Yan Cao1144.30
Guantao Chen210725.00