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A Sublinear Bound on the Cop Throttling Number of a Graph

Combinatorics 2019-01-28 v1 Discrete Mathematics

Abstract

We provide a sublinear bound on the cop throttling number of a connected graph. Related to the graph searching game Cops and Robbers, the cop throttling number, written thc(G)\mathrm{th}_c(G), is given by thc(G)=mink{k+captk(G)}\mathrm{th}_c(G)=\min_k\{k+\mathrm{capt}_k(G)\}, in which captk(G)\mathrm{capt}_k(G) is the kk-capture time, or the length of a game of Cops and Robbers with kk cops on the graph GG, assuming both players play optimally. No general sublinear bound was known on the cop throttling number of a connected graph. Towards a question asked by Breen et al., we prove that thc(G)(2+o(1))nW(log(n))log(n),\mathrm{th}_c(G)\leq \frac{(2+o(1))n\sqrt{W(\log(n))}}{\sqrt{\log(n)}}, where W=W(x)W=W(x) is the Lambert W function.

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Cite

@article{arxiv.1901.09011,
  title  = {A Sublinear Bound on the Cop Throttling Number of a Graph},
  author = {Anthony Bonato and Sean English},
  journal= {arXiv preprint arXiv:1901.09011},
  year   = {2019}
}

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6 pages