arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1509.03092math.CO
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三次图的边分解为四边双星的副本

On edge-decomposition of cubic graphs into copies of the double-star with four edges

Saieed Akbari, Hamidreza Maimani, Abbas Seify

摘要:

一棵树只包含两个非悬垂顶点,称为双星。设$k_1$和$k_2$是两个正整数。度序列为$(k_1+1, k_2+1, 1, \ldots, 1)$的双星记为$S_{k_1, k_2}$。如果$G$是一个三次图并且有一个$S$ -分解,对于一个双星$S$,则$S$同构于$S_{1,1}$,$S_{1,2}$或$S_{2,2}$。已知三次图有$S_{1,1}$ -分解当且仅当它包含完美匹配。本文研究了三次图的$S_{1,2}$ -分解。首先,我们给出了三次图存在$S_{1,2}$ -分解的一些必要条件。然后证明了每一个具有$α(G)= \frac{3n}{8}$的$n$阶无$\{C_3, C_5, C_7\}$三次图都有一个$S_{1,2}$ -分解,其中$α(G)$表示$G$的独立数.最后,我们得到了$r$ -正则图的$S_{1,r-1}$ -分解的一些结果.

英文摘要:

A tree containing exactly two non-pendant vertices is called a double-star. Let $k_1$ and $k_2$ be two positive integers. The double-star with degree sequence $(k_1+1, k_2+1, 1, \ldots, 1)$ is denoted by $S_{k_1, k_2}$. If $G$ is a cubic graph and has an $S$-decomposition, for a double-star $S$, then $S$ is isomorphic to $S_{1,1}$, $S_{1,2}$ or $S_{2,2}$. It is known that a cubic graph has an $S_{1,1}$-decomposition if and only if it contains a perfect matching. In this paper we study the $S_{1,2}$-decomposition of cubic graphs. First, we present some necessary conditions for the existence of an $S_{1,2}$-decomposition in cubic graphs. Then we prove that every $\{C_3, C_5, C_7\}$-free cubic graph of order $n$ with $α(G)= \frac{3n}{8}$ has an $S_{1,2}$-decomposition, where $α(G)$ denotes the independence number of $G$. Finally, we obtain some results on the $S_{1,r-1}$-decomposition of $r$-regular graphs.

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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