摘要
给出了一些星色数为4的平面图，它们不含有轮图作为子图．这回答了Zhu的一个问题，给出了一类4连通平面图其星色数在3与4之间，这也回答了Abbott和Zhou的一个问题．应用图的同态概念，讨论了某些图的字典积的星色数，证明了一个图及其补图的星色数的和与积所满足的两个不等式．
It is proven in this paper that some planar graphs have star chromatic number 4but do not have an odd wheel graph as their subgraph. This answers one question of Zhu. Infinitelymaily 4-connected planar graphs with star chromatic number between 3 and 4 are also provided, whichanswers a question asked by Abbott and Zhou. The star chromatic number of the wreath productof some graphs are studied furtherly by graph homomorphisms. Two inequalities on the sum andproduct of the star chromatic numbers of a graph and its complement are proved.
出处
《数学进展》
CSCD
北大核心
1999年第3期259-265,共7页
Advances in Mathematics（China）
关键词
着色
星色数
字典积
同态
补图
图
平面图
:(k, d)-coloring
star chromatic number
wreath product
homomorphism
