English

The $m$-bipartite Ramsey number $BR_m(H_1,H_2)$

Combinatorics 2022-02-11 v1

Abstract

In a (G1,G2)(G^1,G^2) coloring of a graph GG, every edge of GG is in G1G^1 or G2G^2. For two bipartite graphs H1H_1 and H2H_2, the bipartite Ramsey number BR(H1,H2)BR(H_1, H_2) is the least integer b1b\geq 1, such that for every (G1,G2)(G^1, G^2) coloring of the complete bipartite graph Kb,bK_{b,b}, results in either H1G1H_1\subseteq G^1 or H2G2H_2\subseteq G^2. As another view, for bipartite graphs H1H_1 and H2H_2 and a positive integer mm, the mm-bipartite Ramsey number BRm(H1,H2)BR_m(H_1, H_2) of H1H_1 and H2H_2 is the least integer nn, such that every subgraph GG of Km,nK_{m,n} results in H1GH_1\subseteq G or H2GH_2\subseteq \overline{G}. The size of mm-bipartite Ramsey number BRm(K2,2,K2,2)BR_m(K_{2,2}, K_{2,2}), the size of mm-bipartite Ramsey number BRm(K2,2,K3,3)BR_m(K_{2,2}, K_{3,3}) and the size of mm-bipartite Ramsey number BRm(K3,3,K3,3)BR_m(K_{3,3}, K_{3,3}) have been computed in several articles up to now. In this paper we determine the exact value of BRm(K2,2,K4,4)BR_m(K_{2,2}, K_{4,4}) for each m2m\geq 2.

Keywords

Cite

@article{arxiv.2202.04921,
  title  = {The $m$-bipartite Ramsey number $BR_m(H_1,H_2)$},
  author = {Yaser Rowshan},
  journal= {arXiv preprint arXiv:2202.04921},
  year   = {2022}
}