Title
Edge Lower Bounds for List Critical Graphs, Via Discharging.
Abstract
A graph G is k-critical if G is not (k − 1)-colorable, but every proper subgraph of G is (k − 1)-colorable. A graph G is k-choosable if G has an L-coloring from every list assignment L with |L(v)|=k for all v, and a graph G is k-list-critical if G is not (k−1)-choosable, but every proper subgraph of G is (k−1)-choosable. The problem of determining the minimum number of edges in a k-critical graph with n vertices has been widely studied, starting with work of Gallai and culminating with the seminal results of Kostochka and Yancey, who essentially solved the problem. In this paper, we improve the best known lower bound on the number of edges in a k-list-critical graph. In fact, our result on k-list-critical graphs is derived from a lower bound on the number of edges in a graph with Alon–Tarsi number at least k. Our proof uses the discharging method, which makes it simpler and more modular than previous work in this area.
Year
DOI
Venue
2018
10.1007/s00493-016-3584-6
Combinatorica
Keywords
Field
DocType
05C15
Discrete mathematics,Combinatorics,Graph toughness,Line graph,Graph power,Bound graph,Graph factorization,Cycle graph,Factor-critical graph,Mathematics,Complement graph
Journal
Volume
Issue
ISSN
38
5
0209-9683
Citations 
PageRank 
References 
0
0.34
13
Authors
2
Name
Order
Citations
PageRank
Daniel W. Cranston117225.11
Landon Rabern25914.16