English

Counting spanning subgraphs in dense hypergraphs

Combinatorics 2024-11-20 v2

Abstract

We give a simple method to estimate the number of distinct copies of some classes of spanning subgraphs in hypergraphs with high minimum degree. In particular, for each k2k\geq 2 and 1k11\leq \ell\leq k-1, we show that every kk-graph on nn vertices with minimum codegree at least \cases{\left(\dfrac{1}{2}+o(1)\right)n & if $(k-\ell)\mid k$,\\ & \\ \left(\dfrac{1}{\lceil \frac{k}{k-\ell}\rceil(k-\ell)}+o(1)\right)n & if $(k-\ell)\nmid k$,} contains exp(nlognΘ(n))\exp(n\log n-\Theta(n)) Hamilton \ell-cycles as long as (k)n(k-\ell)\mid n. When (k)k(k-\ell)\mid k this gives a simple proof of a result of Glock, Gould, Joos, K\"uhn and Osthus, while, when (k)k(k-\ell)\nmid k this gives a weaker count than that given by Ferber, Hardiman and Mond or, when <k/2\ell<k/2, by Ferber, Krivelevich and Sudakov, but one that holds for an asymptotically optimal minimum codegree bound.

Keywords

Cite

@article{arxiv.2308.07195,
  title  = {Counting spanning subgraphs in dense hypergraphs},
  author = {Richard Montgomery and Matías Pavez-Signé},
  journal= {arXiv preprint arXiv:2308.07195},
  year   = {2024}
}
R2 v1 2026-06-28T11:55:13.463Z