English

Eternally surrounding a robber

Combinatorics 2025-08-15 v3

Abstract

We introduce the bodyguard problem for graphs. This is a variation of Surrounding Cops and Robber but, in this model, a smallest possible group of bodyguards must surround the president and then maintain this protection indefinitely. We investigate some elementary bounds, then solve this problem for the infinite graph families of complete graphs, wheels, trees, cycles, complete multipartite graphs, and two-dimensional grids. We also examine the problem in more general Cartesian, strong, and lexicographic products.

Keywords

Cite

@article{arxiv.2408.10452,
  title  = {Eternally surrounding a robber},
  author = {Nancy E. Clarke and Danny Dyer and William Kellough},
  journal= {arXiv preprint arXiv:2408.10452},
  year   = {2025}
}

Comments

26 pages, 3 figures

R2 v1 2026-06-28T18:17:32.059Z