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北美退伍军人节(Veterans Day),12 日无更新
arXiv 1002.0661math.CO
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关于曲面中图的限制匹配

On the restricted matching of graphs in surfaces

Qiuli Li, Heping Zhang

摘要:

一个至少有$2m+2n+2$个顶点的连通图$G$称为具有性质$E(m,n)$,如果对于任意两个大小分别为$m$和$n$的不相交匹配$M$和$N$,$G$具有完美匹配$F$,使得$M\subseteq F$和$N\cap F=\varnothing$。特别地,具有$E(m,0)$的图是$m$ -可扩展的。设$μ(Σ)$是最小整数$k$,使得嵌入在曲面$Σ$上的图都不是$k$ -可扩的. Aldred和Plummer已经证明了嵌入在曲面$Σ$上的图都不是$E(μ(Σ)-1,1)$,这些曲面包括球面、射影平面、环面和Klein瓶。在本文中,我们表明,这一结果始终适用于任何曲面。进一步证明了如果图$G$嵌入到曲面上有足够多的顶点,则$G$对每个整数$k\geq 4$都不具有性质$E(k-1,1)$,这意味着$G$不是$k$ -可扩的.在$k=4$的情况下,我们立即得到了Aldred等人最近得到的一个主要结果。

英文摘要:

A connected graph $G$ with at least $2m+2n+2$ vertices is said to have property $E(m,n)$ if, for any two disjoint matchings $M$ and $N$ of size $m$ and $n$ respectively, $G$ has a perfect matching $F$ such that $M\subseteq F$ and $N\cap F=\varnothing$. In particular, a graph with $E(m,0)$ is $m$-extendable. Let $μ(Σ)$ be the smallest integer $k$ such that no graphs embedded on a surface $Σ$ are $k$-extendable. Aldred and Plummer have proved that no graphs embedded on the surfaces $Σ$ such as the sphere, the projective plane, the torus, and the Klein bottle are $E(μ(Σ)-1,1)$. In this paper, we show that this result always holds for any surface. Furthermore, we obtain that if a graph $G$ embedded on a surface has sufficiently many vertices, then $G$ has no property $E(k-1,1)$ for each integer $k\geq 4$, which implies that $G$ is not $k$-extendable. In the case of $k=4$, we get immediately a main result that Aldred et al. recently obtained.

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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