Chunchao Fan

activity

20242026

collaborators

4 papers

math.CO2026

An improved double-exponential lower bound for $r_{4} (5, n)$

Chunchao Fan, Mingze Li, Qizhong Lin +1

The Ramsey number $r_{k} (s, n)$ is the smallest integer $N$ such that every $N$ -vertex $k$ -graph contains either a copy of $K_{s}^{(k)}$ or an independent set of size $n$ . A well-known…

math.CO2026

Ramsey lower bounds for bounded degree hypergraphs

Chunchao Fan, Qizhong Lin

We prove that for all $k \geq 3$ and any integers $I^, n$ with $n \geq 2^{I^} ,$ there exists a $k$ -graph on $n$ vertices with maximum degree at most $I^$ such that $r(H)\geq\tw_{k-1}(c…

math.CO2025

Asymptotically optimal Ramsey goodness of sparse graphs versus odd cycles and paths

Chunchao Fan, Qizhong Lin

A fundamental problem in graph Ramsey theory is to determine, for sparse graphs $G$ on $n$ vertices, the minimal $n$ such that $G$ is Ramsey-good for odd cycles $C_{k}$ and paths $P_…

math.CO2024

New bounds of two hypergraph Ramsey problems

Chunchao Fan, Xinyu Hu, Qizhong Lin +1

We focus on two hypergraph Ramsey problems. First, we consider the ErdÅs-Hajnal function $r_{k} (k + 1, t; n)$ . In 1972, ErdÅs and Hajnal conjectured that the tower growth rate of $r_k(…

An improved double-exponential lower bound for r4​(5,n)

Ramsey lower bounds for bounded degree hypergraphs

Asymptotically optimal Ramsey goodness of sparse graphs versus odd cycles and paths

New bounds of two hypergraph Ramsey problems

An improved double-exponential lower bound for $r_{4} (5, n)$