English

Positive codegree thresholds for perfect matchings in hypergraphs

Combinatorics 2025-05-26 v1

Abstract

We give, for each k3k \geq 3, the precise best possible minimum positive codegree condition for a perfect matching in a large kk-uniform hypergraph HH on nn vertices. Specifically we show that, if nn is sufficiently large and divisible by kk, and HH has minimum positive codegree δ+(H)k1kn(k2)\delta^+(H) \geq \frac{k-1}{k}n - (k-2) and no isolated vertices, then HH contains a perfect matching. For k=3k=3 this was previously established by Halfpap and Magnan, who also gave bounds for k4k \geq 4 which were tight up to an additive constant.

Keywords

Cite

@article{arxiv.2505.17981,
  title  = {Positive codegree thresholds for perfect matchings in hypergraphs},
  author = {Richard Mycroft and Camila Zárate-Guerén},
  journal= {arXiv preprint arXiv:2505.17981},
  year   = {2025}
}

Comments

9 pages

R2 v1 2026-07-01T02:34:03.728Z