Shengjie Xie

activity

20242026

collaborators

4 papers

math.CO2026

Hypergraphs without Subgraphs of Given Connectivity

Jie Ma, Shengjie Xie, Zhiheng Zheng

In this paper, we study the problem of determining the maximum number $F_{r} (n, k)$ of edges in an $n$ -vertex $r$ -uniform hypergraph that contains no $(k + 1)$ -connected subgraph. The g…

math.CO2025

An exponential improvement for Ramsey lower bounds

Jie Ma, Wujie Shen, Shengjie Xie

We prove a new lower bound on the Ramsey number $r (ℓ, C ℓ)$ for any constant $C > 1$ and sufficiently large $ℓ$ , showing that there exists $ε = ε (C) > 0$ s…

math.CO2024

Discrepancies of perfect matchings in hypergraphs

Hongliang Lu, Jie Ma, Shengjie Xie

In this paper, we determine the minimum degree threshold of perfect matchings with high discrepancy in $r$ -edge-colored $k$ -uniform hypergraphs for all $k \geq 3$ and $r \geq 2$ , the…

math.CO2024

Finding irregular subgraphs via local adjustments

Jie Ma, Shengjie Xie

For a graph $H$ , let $m (H, k)$ denote the number of vertices of degree $k$ in $H$ . A conjecture of Alon and Wei states that for any $d \geq 3$ , every $n$ -vertex $d$ -regular graph con…