English

Cops and robbers on $2K_2$-free graphs

Combinatorics 2025-10-29 v2 Discrete Mathematics

Abstract

We prove that the cop number of any 2K22K_2-free graph is at most 2, proving a conjecture of Sivaraman and Testa. We also show that the upper bound of 33 on the cop number of 2K1+K22K_1+K_2-free (co-diamond--free) graphs is best possible.

Keywords

Cite

@article{arxiv.2001.03124,
  title  = {Cops and robbers on $2K_2$-free graphs},
  author = {Jérémie Turcotte},
  journal= {arXiv preprint arXiv:2001.03124},
  year   = {2025}
}

Comments

10 pages, 1 figure

R2 v1 2026-06-23T13:07:16.974Z