English

The bipartite Ramsey number $br(C_{2n}, C_{2m})$

Combinatorics 2023-01-31 v2

Abstract

Given bipartite graphs H1H_1, \dots , HkH_k, the bipartite Ramsey number br(H1,,Hk)br(H_1,\dots, H_k) is the minimum integer NN such that any kk-edge-coloring of complete bipartite graph KN,NK_{N, N} contains a monochromatic HiH_i in color ii for 1ik1\le i\le k. There are considerable results on asymptotic values of bipartite Ramsey numbers of cycles. For exact value, Zhang-Sun \cite{Zhangs} determined br(C4,C2n)br(C_4, C_{2n}), Zhang-Sun-Wu \cite{Zhangsw} determined br(C6,C2n)br(C_6, C_{2n}), and Gholami-Rowshan \cite{GR} determined br(C8,C2n)br(C_8, C_{2n}). In this paper, we solve all remaining cases and give the exact values of br(C2n,C2m)br(C_{2n}, C_{2m}) for all nm5n\ge m\ge 5, this answers a question concerned by Buci\'c-Letzter-Sudakov \cite{BLS}, Gholami-Rowshan \cite{GR}, Zhang-Sun \cite{Zhangs}, and Zhang-Sun-Wu \cite{Zhangsw}.

Keywords

Cite

@article{arxiv.2112.14960,
  title  = {The bipartite Ramsey number $br(C_{2n}, C_{2m})$},
  author = {Zilong Yan and Yuejian Peng},
  journal= {arXiv preprint arXiv:2112.14960},
  year   = {2023}
}