English

Cops and robbers on chess graphs

Combinatorics 2025-09-24 v1

Abstract

Cops and robbers is a pursuit-evasion game played on graphs. We completely classify the cop numbers for n×nn \times n knight graphs and queen graphs. This completes the classification of the cop numbers for all n×nn \times n classical chess graphs. As a corollary, we resolve an open problem about the monotonicity of cc(Qn\mathcal{Q}_n). Moreover, we introduce \emph{royal graphs}, a generalization of chess graphs for arbitrary piece movements, which models real-life movement constraints. We give results on the cop numbers for these families.

Keywords

Cite

@article{arxiv.2509.18516,
  title  = {Cops and robbers on chess graphs},
  author = {Sally Ambrose and Evan Angelone and Jacob Chen and Daniel Ma and Arturo Ortiz San Miguel and Wraven Watanabe and Stephen Whitcomb and Shanghao Wu},
  journal= {arXiv preprint arXiv:2509.18516},
  year   = {2025}
}

Comments

10 pages, 2 figures

R2 v1 2026-07-01T05:51:09.985Z