English

Connected matching in graphs with independence number two

Combinatorics 2024-09-11 v1

Abstract

A matching MM in a graph GG is {\em connected} if GG has an edge linking each pair of edges in MM. The problem to find large connected matchings in graphs GG with α(G)=2\alpha(G)=2 is closely related to Hadwiger's conjecture for graphs with independence number 2. The problem of finding a large connected matching in a general graph is NP-hard. F{\"u}redi et al. in 2005 conjectured that each (4t1)(4t-1)-vertex graph GG with α(G)=2\alpha(G)=2 contains a connected matching of size at least tt. Cambie recently showed that if this conjecture is false, then so is Hadwiger's conjecture. In this paper, we present a number of properties possessed by a counterexample to F{\"u}redi et al.'s conjecture, and then using these properties, we prove that F{\"u}redi et al.'s conjecture holds for t22t\leq22.

Keywords

Cite

@article{arxiv.2409.05920,
  title  = {Connected matching in graphs with independence number two},
  author = {Rong Chen and Zijian Deng},
  journal= {arXiv preprint arXiv:2409.05920},
  year   = {2024}
}
R2 v1 2026-06-28T18:39:00.737Z