Xinyu Hu

activity

20242026

collaborators

8 papers

math.CO2026

New Tower-Type Lower Bounds for Hypergraph Ramsey Numbers

Hanzhi Bai, Longma Du, Xinyu Hu +2

The Ramsey number $r_{k} (s, m)$ is the smallest $N$ such that any red/blue coloring of the $k$ -subsets of $[N]$ contains a red $s$ -set or a blue $m$ -set. For fixed $k$ and $s$ , and fo…

math.CO2026

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

Longma Du, Xinyu Hu, Ruilong Liu +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 $n$ . We prove that…

math.CO2026

A step towards the Ramsey-TurÃ¡n conjecture for $K_{3}$ and $K_{6}$

Xinyu Hu, Qizhong Lin

Ramsey-TurÃ¡n type problems were initiated by ErdÅs and SÃ³s in 1969. Given integers $p, q \geq 2$ , a graph $G$ is $(K_{p}, K_{q})$ -free if there exists a red/blue edge coloring of $G$ su…

math.CO2026

A Note on Generalized ErdÅs-Rogers Problems

Longma Du, Xinyu Hu, Ruilong Liu +1

For a $k$ -uniform hypergraph $F$ and positive integers $s$ and $N$ , the generalized ErdÅs-Rogers function $f_{F, s}^{(k)} (N)$ denotes the largest integer $m$ such that every $K_s^{…

math.CO2026

A step towards the ErdÅs-Rogers problem

Longma Du, Xinyu Hu, Ruilong Liu +1

For $2 \leq k \leq t < s$ , the ErdÅs-Rogers function $f_{t, s}^{(k)} (N)$ denotes the largest $m$ such that every $K_{s}^{(k)}$ -free $k$ -graph on $N$ vertices contains a $K_{t}^{(k)}$ -free in…

math.CO2026

Spectral bounds for the independence number of graphs and even uniform hypergraphs

Xinyu Hu, Jiang Zhou, Changjiang Bu

In this paper, we give spectral upper bounds for the independence number of even uniform hypergraphs and graphs, extend the Hoffman bound to even uniform hypergraphs, and give a si…

New Tower-Type Lower Bounds for Hypergraph Ramsey Numbers

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

A step towards the Ramsey-TurÃ¡n conjecture for K3​ and K6​

A Note on Generalized ErdÅs-Rogers Problems

A step towards the ErdÅs-Rogers problem

Spectral bounds for the independence number of graphs and even uniform hypergraphs

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

A step towards the Ramsey-TurÃ¡n conjecture for $K_{3}$ and $K_{6}$

A Note on Generalized ErdÅs-Rogers Problems

A step towards the ErdÅs-Rogers problem