English

Satisfying sequences for rainbow partite matchings

Combinatorics 2025-02-06 v1 Discrete Mathematics

Abstract

Let F1,,Fs[n]k\mathcal F_1,\ldots, \mathcal F_s\subset [n]^k be a collection of ss families. In this paper, we address the following question: for which sequences f1,,fsf_1,\ldots, f_s the conditions \ffi>fi|\ff_i|>f_i imply that the families contain a rainbow matching, that is, there are pairwise disjoint F1\ff1,Fs\ffsF_1\in \ff_1,\ldots F_s\in \ff_s? We call such sequences {\em satisfying}. Kiselev and the first author verified the conjecture of Aharoni and Howard and showed that f1==fs=(s1)nk1f_1 = \ldots = f_s=(s-1)n^{k-1} is satisfying for s>470s>470. This is the best possible if the restriction is uniform over all families. However, it turns out that much more can be said about asymmetric restrictions. In this paper, we investigate this question in several regimes and in particular answer the questions asked by Kiselev and Kupavskii. We use a variety of methods, including concentration and anticoncentration results, spread approximations, and Combinatorial Nullstellenzats.

Keywords

Cite

@article{arxiv.2502.03105,
  title  = {Satisfying sequences for rainbow partite matchings},
  author = {Andrey Kupavskii and Elizaveta Popova},
  journal= {arXiv preprint arXiv:2502.03105},
  year   = {2025}
}
R2 v1 2026-06-28T21:33:21.876Z