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arXiv · 2508.17683

An analogue of the Erd{\H o}s Matching Conjecture for permutations with fixed number of cycles

Cheng Yeaw Ku·Kok Bin Wong
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Abstract

Let $S_{n}$ denote the set of permutations of $[n]=\{1,2,\dots, n\}$. For each integer $k\geq 1$, let $S_{n,k}$ be the set of all permutations of $[n]$ with exactly $k$ disjoint cycles. A subset $H\subseteq S_{n,k}$ is to be a matching if $\pi_1$ and $\pi_2$ do not have any common cycles for all distinct $\pi_1,\pi_2\in H$. The matching number of a family $\mathcal A\subseteq S_{n,k}$ is denoted by $\nu_{p}(\mathcal A)$ and is defined to be the size of the largest matching in $\mathcal A$. In this paper, we determine the maximum size of a family $\mathcal A\subseteq S_{n,k}$ subject to the condition $\nu_p(\mathcal A)\leq s$.

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Cheng Yeaw Ku, Kok Bin Wong. 2025-08-25. An analogue of the Erd{\H o}s Matching Conjecture for permutations with fixed number of cycles. https://arxiv.org/abs/2508.17683

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