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北美退伍军人节(Veterans Day),12 日无更新
arXiv 1507.01080math.CO
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图的Grundy数的更多界

More bounds for the Grundy number of graphs

Zixing Tang, Baoyindureng Wu, Lin Hu, Manoucheher Zaker

摘要:

图$G=(V,E)$的着色是将$V$划分为独立的集合或色类的划分$\{V_1, V_2, \ldots, V_k\}$。顶点$v\in V_i$是Grundy顶点,如果它与每个$j<i$的每个颜色类$V_j$中的至少一个顶点相邻。一个图的染色是Grundy染色,如果每个顶点都是Grundy顶点,并且图的Grundy数$Γ(G)$是一个图的Grundy染色的最大颜色数.本文给出了图的Grundy数的两个新的上界和著名的Nordhaus-Gaddum定理的一个更强的版本。此外,通过支持Zaker的一个猜想,我们给出了无$\{P_{4}, C_4\}$图的一个新的刻画,即对任何无$C_4$的图$G$,$Γ(G)\geq δ(G)+1$.

英文摘要:

A coloring of a graph $G=(V,E)$ is a partition $\{V_1, V_2, \ldots, V_k\}$ of $V$ into independent sets or color classes. A vertex $v\in V_i$ is a Grundy vertex if it is adjacent to at least one vertex in each color class $V_j$ for every $j<i$. A coloring is a Grundy coloring if every vertex is a Grundy vertex, and the Grundy number $Γ(G)$ of a graph $G$ is the maximum number of colors in a Grundy coloring. We provide two new upper bounds on Grundy number of a graph and a stronger version of the well-known Nordhaus-Gaddum theorem. In addition, we give a new characterization for a $\{P_{4}, C_4\}$-free graph by supporting a conjecture of Zaker, which says that $Γ(G)\geq δ(G)+1$ for any $C_4$-free graph $G$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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