English

Off-Diagonal Ramsey Numbers for Linear Hypergraphs

Combinatorics 2025-07-10 v2

Abstract

We study off-diagonal Ramsey numbers r(H,Kn(k))r(H, K_n^{(k)}) of kk-uniform hypergraphs, where HH is a fixed linear kk-uniform hypergraph and Kn(k)K_n^{(k)} is complete on nn vertices. Recently, Conlon et al.\ disproved the folklore conjecture that r(H,Kn(3))r(H, K_n^{(3)}) always grows polynomially in nn. In this paper we show that much larger growth rates are possible in higher uniformity. In uniformity k4k\ge 4, we prove that for any constant C>0C>0, there exists a linear kk-uniform hypergraph HH for which r(H,Kn(k))twrk2(2(logn)C).r(H,K_n^{(k)}) \geq \textup{twr}_{k-2}(2^{(\log n)^C}).

Keywords

Cite

@article{arxiv.2507.05641,
  title  = {Off-Diagonal Ramsey Numbers for Linear Hypergraphs},
  author = {Xiaoyu He and Jiaxi Nie and Yuval Wigderson and Hung-Hsun Hans Yu},
  journal= {arXiv preprint arXiv:2507.05641},
  year   = {2025}
}

Comments

15 pages, 4 figures