English

Matchings in hypergraphs via Ore-degree conditions

Combinatorics 2026-04-14 v2

Abstract

Let H([n]r)\mathcal{H} \subseteq \binom{[n]}{r} be an rr-uniform hypergraph on vertex set [n]={1,2,,n}[n] = \{1,2,\dots, n\}. For an rr-set of vertices S[n]S \subseteq [n], the \emph{degree} of SS is defined as deg(S)=vSdeg(v)\textrm{deg}(S)=\sum_{v \in S}\textrm{deg}(v) and the minimum of deg(S)\textrm{deg}(S) over all non-edge rr-subsets S∉E(H)S \not \in E(\mathcal{H}) of V(H)V({\cal H}) is the {\it Ore-degree} of H{\cal H}, denoted by σr(H){\sigma_r}({\cal H}). We prove several Ore-degree results about existence of matchings in hypergraphs: (1) For n2r+2n\geq 2r+2, if H{\cal H} is an intersecting rr-uniform hypergraph on nn vertices, then σr(H)r(n2r2)\sigma_r({\cal H})\leq r{n-2 \choose r-2}, and there is equality only when H{\cal H} is a 11-star. (2) For r3r\geq 3 and n4r2n\geq 4r^2, if is a non-trivial intersecting rr-uniform hypergraph on nn vertices, then σr(H)r((n2r2)(nr2r2))\sigma_r({\cal H})\leq r\left({n-2 \choose r-2}-{n-r-2 \choose r-2}\right). (3) For s2s\geq 2 and n3r2(s1)n\geq 3r^2(s-1), if H{\cal H} is an rr-uniform hypergraph on nn vertices and σr(H)>r((n1r1)(nsr1))\sigma_r({\cal H})>r\left({n-1 \choose r-1}-{n-s \choose r-1}\right), then H{\cal H} contains ss pairwise disjoint edges.

Keywords

Cite

@article{arxiv.2603.06415,
  title  = {Matchings in hypergraphs via Ore-degree conditions},
  author = {József Balogh and Cory Palmer and Ghaffar Raeisi},
  journal= {arXiv preprint arXiv:2603.06415},
  year   = {2026}
}

Comments

Update to the statement of Conjecture 2

R2 v1 2026-07-01T11:07:10.839Z