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arXiv 1503.03671math.COmath.LO
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彩虹匹配与集合代数

Rainbow matchings and algebras of sets

Gabriel Nivasch, Eran Omri

摘要:

Grinblat(2002)在集合代数的背景下提出了以下问题:什么是最小数$\mathfrak v = \mathfrak v(n)$,使得,如果$A_1, \ldots, A_n$是公共有限基集$X$上的$n$等价关系,使得对于每个$i$,至少有$X$的$\mathfrak v$元素属于大小大于$1$的$A_i$ -等价类,则$X$具有彩虹匹配-一组$2n$不同元素$a_1, b_1, \ldots, a_n, b_n$,使得$a_i$是$A_i$ -对于每个$i$,等效于$b_i$?格林布拉特已经证明了$\mathfrak v(n) \le 10n/3 + O(\sqrt{n})$。他询问是否所有$n\ge 4$均使用$\mathfrak v(n) = 3n-2$。在本文中,我们改进的上限(所有足够大的$n$)到$\mathfrak v(n) \le 16n/5 + O(1)$。

英文摘要:

Grinblat (2002) asks the following question in the context of algebras of sets: What is the smallest number $\mathfrak v = \mathfrak v(n)$ such that, if $A_1, \ldots, A_n$ are $n$ equivalence relations on a common finite ground set $X$, such that for each $i$ there are at least $\mathfrak v$ elements of $X$ that belong to $A_i$-equivalence classes of size larger than $1$, then $X$ has a rainbow matching---a set of $2n$ distinct elements $a_1, b_1, \ldots, a_n, b_n$, such that $a_i$ is $A_i$-equivalent to $b_i$ for each $i$? Grinblat has shown that $\mathfrak v(n) \le 10n/3 + O(\sqrt{n})$. He asks whether $\mathfrak v(n) = 3n-2$ for all $n\ge 4$. In this paper we improve the upper bound (for all large enough $n$) to $\mathfrak v(n) \le 16n/5 + O(1)$.

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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