English

Cycle Ramsey numbers for random graphs

Combinatorics 2018-09-21 v2

Abstract

Let CnC_{n} be a cycle of length nn. As an application of Szemer\'{e}di's regularity lemma, {\L}uczak (R(Cn,Cn,Cn)(4+o(1))nR(C_n,C_n,C_n)\leq (4+o(1))n, J. Combin. Theory Ser. B, 75 (1999), 174--187) in fact established that K(8+o(1))n(C2n+1,C2n+1,C2n+1)K_{(8+o(1))n}\to(C_{2n+1},C_{2n+1},C_{2n+1}). In this paper, we strengthen several results involving cycles. Let G(n,p)\mathcal{G}(n,p) be the random graph. We prove that for fixed 0<p10<p\le1, and integers n1n_1, n2n_2 and n3n_3 with n1n2n3n_1\ge n_2\ge n_3, it holds that for any sufficiently small δ>0\delta>0, there exists an integer n0n_0 such that for all integer n3>n0n_3>n_0, we have a.a.s. that \begin{align*} \mathcal{G}((8+\delta)n_1,p) \to (C_{2n_1+1},C_{2n_2+1},C_{2n_3+1}). \end{align*} Moreover, we prove that for fixed 0<p10<p\le1 and integers n1n2n3>0n_1\ge n_2\ge n_3>0 with same order, i.e. n2=Θ(n1)n_2=\Theta(n_1) and n3=Θ(n1)n_3=\Theta(n_1), we have a.a.s. that \begin{align*} \mathcal{G}(2n_1+n_2+n_3+o(1)n_1,p) \to (C_{2n_1},C_{2n_2},C_{2n_3}). \end{align*} Similar results for the two color case are also obtained.

Keywords

Cite

@article{arxiv.1809.00779,
  title  = {Cycle Ramsey numbers for random graphs},
  author = {Meng Liu and Yusheng Li and Qizhong Lin and Chunlin You},
  journal= {arXiv preprint arXiv:1809.00779},
  year   = {2018}
}
R2 v1 2026-06-23T03:53:14.469Z