English

Tight bounds for rainbow partial $F$-tiling in edge-colored complete hypergraphs

Combinatorics 2024-06-24 v2

Abstract

For an rr-graph FF and integers n,tn,t satisfying tn/v(F)t \le n/v(F), let ar(n,tF)\mathrm{ar}(n,tF) denote the minimum integer NN such that every edge-coloring of KnrK_{n}^{r} using NN colors contains a rainbow copy of tFtF, where tFtF is the rr-graphs consisting of tt vertex-disjoint copies of FF. The case t=1t=1 is the classical anti-Ramsey problem proposed by Erd\H{o}s--Simonovits--S\'{o}s~\cite{ESS75}. When FF is a single edge, this becomes the rainbow matching problem introduced by Schiermeyer~\cite{Sch04} and \"{O}zkahya--Young~\cite{OY13}. We conduct a systematic study of ar(n,tF)\mathrm{ar}(n,tF) for the case where tt is much smaller than ex(n,F)/nr1\mathrm{ex}(n,F)/n^{r-1}. Our first main result provides a reduction of ar(n,tF)\mathrm{ar}(n,tF) to ar(n,2F)\mathrm{ar}(n,2F) when FF is bounded and smooth, two properties satisfied by most previously studied hypergraphs. Complementing the first result, the second main result, which utilizes gaps between Tur\'{a}n numbers, determines ar(n,tF)\mathrm{ar}(n,tF) for relatively smaller tt. Together, these two results determine ar(n,tF)\mathrm{ar}(n,tF) for a large class of hypergraphs. Additionally, the latter result has the advantage of being applicable to hypergraphs with unknown Tur\'{a}n densities, such as the famous tetrahedron K43K_{4}^{3}.

Keywords

Cite

@article{arxiv.2406.14083,
  title  = {Tight bounds for rainbow partial $F$-tiling in edge-colored complete hypergraphs},
  author = {Jinghua Deng and Jianfeng Hou and Xizhi Liu and Caihong Yang},
  journal= {arXiv preprint arXiv:2406.14083},
  year   = {2024}
}

Comments

19 pages, 1 figues, comments are welcome

R2 v1 2026-06-28T17:13:04.797Z