English

Random perfect matchings in regular graphs

Combinatorics 2023-11-28 v2

Abstract

We prove that in all regular robust expanders GG every edge is asymptotically equally likely contained in a uniformly chosen perfect matching MM. We also show that given any fixed matching or spanning regular graph NN in GG, the random variable ME(N)|M\cap E(N)| is approximately Poisson distributed. This in particular confirms a conjecture and a question due to Spiro and Surya, and complements results due to Kahn and Kim who proved that in a regular graph every vertex is asymptotically equally likely contained in a uniformly chosen matching. Our proofs rely on the switching method and the fact that simple random walks mix rapidly in robust expanders.

Keywords

Cite

@article{arxiv.2301.10131,
  title  = {Random perfect matchings in regular graphs},
  author = {Bertille Granet and Felix Joos},
  journal= {arXiv preprint arXiv:2301.10131},
  year   = {2023}
}

Comments

8 pages; final version, to appear in Random Structures & Algorithms

R2 v1 2026-06-28T08:18:50.085Z