Title
Average degrees of edge-chromatic critical graphs.
Abstract
Let G be a simple graph, and let Δ(G), d¯(G) and χ′(G) denote the maximum degree, the average degree and the chromatic index of G, respectively. We called G edge-Δ-critical if χ′(G)=Δ(G)+1 and χ′(H)≤Δ(G) for every proper subgraph H of G. Vizing in 1968 conjectured that if G is an edge-Δ-critical graph of order n, then d¯(G)≥Δ(G)−1+3n. We prove that for any edge-Δ-critical graph G, d̄(G)≥min22Δ(G)−3−222+1,3Δ(G)4−2, that is, d¯(G)≥34Δ(G)−2ifΔ(G)≤75;22Δ(G)−3−222+1≈0.7388Δ(G)−1.153ifΔ(G)≥76.This result improves the best known bound 23(Δ(G)+2) obtained by Woodall in 2007 for Δ(G)≥41.
Year
DOI
Venue
2019
10.1016/j.disc.2019.02.014
Discrete Mathematics
Keywords
Field
DocType
Edge-k-coloring,Edge-critical graphs,Vizing’s adjacency lemma
Prime (order theory),Adjacency list,Discrete mathematics,Graph,Edge coloring,Combinatorics,Chromatic scale,Degree (graph theory),Mathematics
Journal
Volume
Issue
ISSN
342
6
0012-365X
Citations 
PageRank 
References 
0
0.34
4
Authors
5
Name
Order
Citations
PageRank
Yan Cao1144.30
Guantao Chen210725.00
Suyun Jiang301.01
Huiqing Liu4184.92
Fuliang Lu556.07