English

Local resilience and Hamiltonicity Maker-Breaker games in random-regular graphs

Combinatorics 2011-02-01 v4 Discrete Mathematics Probability

Abstract

For an increasing monotone graph property \mP\mP the \emph{local resilience} of a graph GG with respect to \mP\mP is the minimal rr for which there exists of a subgraph HGH\subseteq G with all degrees at most rr such that the removal of the edges of HH from GG creates a graph that does not possesses \mP\mP. This notion, which was implicitly studied for some ad-hoc properties, was recently treated in a more systematic way in a paper by Sudakov and Vu. Most research conducted with respect to this distance notion focused on the Binomial random graph model \GNP\GNP and some families of pseudo-random graphs with respect to several graph properties such as containing a perfect matching and being Hamiltonian, to name a few. In this paper we continue to explore the local resilience notion, but turn our attention to random and pseudo-random \emph{regular} graphs of constant degree. We investigate the local resilience of the typical random dd-regular graph with respect to edge and vertex connectivity, containing a perfect matching, and being Hamiltonian. In particular we prove that for every positive ϵ\epsilon and large enough values of dd with high probability the local resilience of the random dd-regular graph, \GND\GND, with respect to being Hamiltonian is at least (1ϵ)d/6(1-\epsilon)d/6. We also prove that for the Binomial random graph model \GNP\GNP, for every positive ϵ>0\epsilon>0 and large enough values of KK, if p>Klnnnp>\frac{K\ln n}{n} then with high probability the local resilience of \GNP\GNP with respect to being Hamiltonian is at least (1ϵ)np/6(1-\epsilon)np/6. Finally, we apply similar techniques to Positional Games and prove that if dd is large enough then with high probability a typical random dd-regular graph GG is such that in the unbiased Maker-Breaker game played on the edges of GG, Maker has a winning strategy to create a Hamilton cycle.

Keywords

Cite

@article{arxiv.0911.4351,
  title  = {Local resilience and Hamiltonicity Maker-Breaker games in random-regular graphs},
  author = {Sonny Ben-Shimon and Michael Krivelevich and Benny Sudakov},
  journal= {arXiv preprint arXiv:0911.4351},
  year   = {2011}
}

Comments

34 pages. 1 figure