论文标题

(p_5,hvn)的色数 - 免费图

The chromatic number of (P_5, HVN )-free graphs

论文作者

Xu, Yian

论文摘要

令$ g $为图。我们使用$χ(g)$和$ω(g)$分别表示$ g $的色数和集团数。 $ p_5 $是5个顶点的路径,而$ hvn $是$ k_4 $,还有另一个顶点,恰好与两个$ k_4 $的顶点相邻。结合一些已知结果,在本文中,我们表明,如果$ g $为$(p_5,\ textit {hvn})$ - 免费,则$χ(g)\ leq \ leq \ max \ {\ min \ {\ min \ {16,ω(g)+3 \},+3 \},ω(g)+1 \ \} $。这种上限几乎是锋利的。

Let $G$ be a graph. We use $χ(G)$ and $ω(G)$ to denote the chromatic number and clique number of $G$ respectively. A $P_5$ is a path on 5 vertices, and an $HVN$ is a $K_4$ together with one more vertex which is adjacent to exactly two vertices of $K_4$. Combining with some known result, in this paper we show that if $G$ is $(P_5, \textit{HVN})$-free, then $χ(G)\leq \max\{\min\{16, ω(G)+3\}, ω(G)+1\}$. This upper bound is almost sharp.

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