English

Transversal packings in families of percolated hypergraphs

Combinatorics 2025-07-18 v1

Abstract

Let FF be a strictly 11-balanced kk-graph on ss vertices with tt edges and δF,dT\delta_{F,d}^T be the infimum of δ>0\delta>0 such that for every α>0\alpha>0 and sufficiently large nNn\in \mathbb{N}, every kk-graph system H={H1,H2,,Htn}\mathbf H=\{H_{1}, H_{2}, \dots ,H_{tn}\} on the same snsn vertices with δd(Hi)(δ+α)(sndkd)\delta_d(H_i)\ge (\delta+\alpha)\binom{sn-d}{k-d}, i[tn]i\in [tn] contains a transversal FF-factor, that is, an FF-factor consisting of exactly one edge from each HiH_i. In this paper we prove the following result. Let H={H1,H2,,Htn}\mathbf{H} =\{H_{1}, H_{2}, \dots ,H_{tn}\} be a kk-graph system where each HiH_{i} is an snsn-vertex kk-graph with δd(Hi)(δF,dT+α)(sndkd)\delta_d(H_i)\ge (\delta_{F,d}^T+\alpha)\binom{sn-d}{k-d}. Then with high probability H(p):={H1(p),H2(p),,Htn(p)}\mathbf{H}(p) :=\{H_{1}(p), H_{2}(p), \dots ,H_{tn}(p)\} contains a transversal FF-factor, where Hi(p)H_i(p) is a random subhypergraph of HiH_i and p=Ω(n1/d1(F)1(logn)1/t)p=\Omega(n^{-1/d_1(F)-1}(\log n)^{1/t}). This extends a recent result by Kelly, M\"{u}yesser and Pokrovskiy, and independently by Joos, Lang and Sanhueza-Matamala. Moreover, the assumption on pp is best possible up to a constant. Along the way, we also obtain a spread version of a result of Pikhurko on perfect matchings in kk-partite kk-graphs.

Keywords

Cite

@article{arxiv.2507.12740,
  title  = {Transversal packings in families of percolated hypergraphs},
  author = {Jie Han and Jie Hu and Shunan Wei and Donglei Yang},
  journal= {arXiv preprint arXiv:2507.12740},
  year   = {2025}
}

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24 pages