Injective Colorings of Graphs with Low Average Degree

被引:36
作者
Cranston, Daniel W. [2 ,3 ]
Kim, Seog-Jin [1 ]
Yu, Gexin [4 ]
机构
[1] Konkuk Univ, Seoul, South Korea
[2] Virginia Commonwealth Univ, Dept Math & Appl Math, Richmond, VA USA
[3] Rutgers State Univ, DIMACS, Piscataway, NJ USA
[4] Coll William & Mary, Williamsburg, VA USA
基金
美国国家科学基金会;
关键词
Injective coloring; Discharging method; Maximum average degree; List coloring; CHROMATIC NUMBER; PLANAR GRAPHS; SQUARE; THEOREM;
D O I
10.1007/s00453-010-9425-x
中图分类号
TP31 [计算机软件];
学科分类号
081202 ; 0835 ;
摘要
Let mad (G) denote the maximum average degree (over all subgraphs) of G and let chi (i) (G) denote the injective chromatic number of G. We prove that if Delta >= 4 and mad (G) < 14/5, then chi i (G) <= Delta +2. When Delta = 3, we show that mad (G) < 36/13 implies chi i (G) <= 5. In contrast, we give a graph G with Delta = 3, mad (G) = 36/13, and chi (i) (G)=6.
引用
收藏
页码:553 / 568
页数:16
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