Ramsey numbers of K_s + mK_t versus K_n
Combinatorics
2026-02-12 v1
Abstract
For integers m >= 1, s >= 0, and t >= 1, let K_s + mK_t denote the join of a clique K_s and m vertex-disjoint copies of K_t. We prove that for fixed m >= 1, t >= 1, and s >= 0, R(K_s + mK_t, K_n) = O( n^{s+t-1} / (log n)^{s+t-2} ). This settles a problem proposed by Liu and Li (2026). Moreover, for (s,t) = (0,3) the bound is tight up to a constant factor, matching the classical result R(K_3, K_n) = Theta( n^2 / log n ) of Kim (1995).
Cite
@article{arxiv.2602.10499,
title = {Ramsey numbers of K_s + mK_t versus K_n},
author = {Lulu Dai and Qizhong Lin},
journal= {arXiv preprint arXiv:2602.10499},
year = {2026}
}