Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4650777 | Discrete Mathematics | 2008 | 17 Pages |
Abstract
A graph G with maximum degree ΔΔ and edge chromatic number χ′(G)>Δχ′(G)>Δ is edge -ΔΔ-critical if χ′(G-e)=Δχ′(G-e)=Δ for every edge e of G . New lower bounds are given for the average degree of an edge-ΔΔ-critical graph, which improve on the best bounds previously known for most values of ΔΔ. Examples of edge-ΔΔ-critical graphs are also given. In almost all cases, there remains a large gap between the best lower bound known and the smallest average degree of any known edge-ΔΔ-critical graph.
Keywords
Related Topics
Physical Sciences and Engineering
Mathematics
Discrete Mathematics and Combinatorics
Authors
Douglas R. Woodall,