Haixiang Zhang

collaborators

5 papers

math.CO2025

The maximum sum of sizes of non-empty cross $L$ -intersecting families

Xiamiao Zhao, Haixiang Zhang, Mei Lu

Let $n$ , $r$ , and $k$ be positive integers such that $k, r \geq 2$ , $L$ a non-empty subset of $[k]$ , and $F_{i} \subseteq (k [ n ])$ for $1 \leq i \leq r$ . We say that…

math.CO2025

Cross-intersection theorems for uniform partitions of finite sets

Tian Yao, Mengyu Cao, Haixiang Zhang

A set partition is $c$ -uniform if every block has size $c$ . Two families of $c$ -uniform partitions of a finite set are said to be cross $t$ -intersecting if two partitions from diff…

math.CO2025

Counting induced subgraphs with given intersection sizes

Haixiang Zhang, Yichen Wang, Xiamiao Zhao +1

Let $F$ be a graph of order $r$ . In this paper, we study the maximum number of induced copies of $F$ with restricted intersections, which highlights the motivation from extremal se…

math.CO2025

Turán type problems for a fixed graph and a linear forest

Haixiang Zhang, Xiamiao Zhao, Mei Lu

Let $F$ be a family of graphs. A graph $G$ is $F$ -free if $G$ does not contain any $F \in F$ as a subgraph. The Turán number, denoted by $ex(n, \mathsc…

math.CO2025

Simplices in $t$ -intersecting families for vector spaces

Haixiang zhang, Mengyu Cao, Mei Lu +1

Let $V$ be an $n$ -dimensional vector space over the finite field $F_{q}$ and $[k V]$ denote the family of all $k$ -dimensional subspaces of $V$ . A family $\mathcal{F}\s…

The maximum sum of sizes of non-empty cross L-intersecting families

Cross-intersection theorems for uniform partitions of finite sets

Counting induced subgraphs with given intersection sizes

Turán type problems for a fixed graph and a linear forest

Simplices in t-intersecting families for vector spaces

The maximum sum of sizes of non-empty cross $L$ -intersecting families

Simplices in $t$ -intersecting families for vector spaces