Sharp Ramsey thresholds for large books

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Authors: Qizhong Lin, Ye Wang
Cited by: 0

Abstract

For graphs G and H, let $G\rightarrow H$ signify that any red/blue edge coloring of G contains a monochromatic H. Let $G(N,p)$ be the random graph of order N and edge probability p. The Ramsey thresholds for fixed graphs have received most attention. In this paper, we consider the Ramsey thresholds in another angle. In particular, we will consider the sharp Ramsey threshold for the large book graph $B_{n}^{(k)}$, which consists of n copies of $K_{k+1}$ all sharing a common $K_{k}$. In particular, for every fixed integer $k\ge2$ and for any real $c>1$, let $N=c2^{k}n$. Then for any real $\gamma>0$, $$lim_{n\rightarrow\infty}Pr(G(N,p)\rightarrow B_{n}^{(k)})=\begin{cases}0&if~p\le\frac{1}{c^{1/k}}(1-\gamma),\\ 1&if~p\ge\frac{1}{c^{1/k}}(1+\gamma).\end{cases}$$ This implies that $r(B_{n}^{(k)})=2^{k}n+o(n)$, and hence especially extends the work of Conlon (2019) and the follow-up work of Conlon, Fox, and Wigderson (2022) on book Ramsey numbers.

Fields of Study & Subjects

Limits and Structures in Graph Theory Advanced Topology and Set Theory Computability Logic AI Algorithms

Publication details

Journal / source
Journal of Combinatorics
Publisher
International Press of Boston
Volume
17
Issue
3
Pages
369–387
Publication date
1 January 2026
Language
EN