东南大学学报（英文版）2008，Vol.24Issue(2)：253-256,4.
图的圆色数的一些结果
Some results on circular chromatic number of a graph
摘要
Abstract
For two integers k and d with (k, d) = 1 and k≥2d, letedge if and only if d ≤ | i -j |≤ k - d. The circular chromaticnumber Xc (G) of a graph G is the minimum of k/d for which Gadmits a homomorphism to Gkd. The relationship between Xc(G -v) and Xc (G)is investigated. In particular, the circular chromaticnumber of Gkd - v for any vertex v is determined. Some graphswith Xc ( G - v) =Xc (G) - 1 for any vertex v and with certainproperties are presented. Some lower bounds for the circularchromatic number of a graph are studied, and a necessary andsufficient condition under which the circular chromatic number ofa graph attains the lower bound X - 1 + 1/α is proved, where X isthe chromatic number of G and α is its independence number.关键词
(k,d)-着色/r-圆着色/圆色数/Mycielski图Key words
(k, d)-coloring/ r-circular-coloring/ circularchromatic number/ Mycielski's graph分类
数理科学引用本文复制引用
吴建专,林文松..图的圆色数的一些结果[J].东南大学学报（英文版）,2008,24(2):253-256,4.基金项目
The National Natural Science Foundation of China(No.10671033). （No.10671033）
