arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1609.09550math.CO
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定向图的Hamilton分解的计数

Counting Hamilton decompositions of oriented graphs

Asaf Ferber, Eoin Long, Benny Sudakov

摘要:

有向图$G$中的Hamilton圈是通过$G$的每个顶点的圈。$G$的Hamilton分解是将其边集划分为不相交的Hamilton圈。在$60$的后期,凯利承认,每一个定期锦标赛都有一个汉密尔顿分解。这个猜想最近被Kühn和Osthus解决了,他们更一般地证明了每个$r$ -正则$n$ -顶点定向图$G$(没有反平行边),对于某个固定的$c>3/8$,具有$r=cn$,有一个Hamilton分解,只要$n=n(c)$足够大。在本文中,我们解决的自然问题估计的$G$分解的数量,并表明这个数字是$n^{(1-o(1))cn^2}$。此外,我们还得到了Kelly猜想的近似形式的一个新的、简单得多的证明。

英文摘要:

A Hamilton cycle in a directed graph $G$ is a cycle that passes through every vertex of $G$. A Hamiltonian decomposition of $G$ is a partition of its edge set into disjoint Hamilton cycles. In the late $60$s Kelly conjectured that every regular tournament has a Hamilton decomposition. This conjecture was recently settled by Kühn and Osthus, who proved more generally that every $r$-regular $n$-vertex oriented graph $G$ (without antiparallel edges) with $r=cn$ for some fixed $c>3/8$ has a Hamiltonian decomposition, provided $n=n(c)$ is sufficiently large. In this paper we address the natural question of estimating the number of such decompositions of $G$ and show that this number is $n^{(1-o(1))cn^2}$. In addition, we also obtain a new and much simpler proof for the approximate version of Kelly's conjecture.

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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