Zichao Dong

collaborators

7 papers

math.CO2026

Sharp bounds on $k$ -wise generalizations of oddtowns and eventowns

Zichao Dong, Minghui Ouyang, Lan Wei

For $I^\pm = (I^\pm_{1}, \dots, I^\pm_{k}) \in F_{2}^{k}$ , an $I^\pm$ -town is a set family in which every $i$ -wise intersection has parity $I^\pm_{i}$ . Denote by $f_{\boldsym…

math.CO2026

A dichotomy for hypergraph Zarankiewicz problems on axis-parallel boxes

Ting-Wei Chao, Zichao Dong, Hong Liu +2

We study the Zarankiewicz problem for $r$ -partite, $r$ -uniform intersection hypergraphs arising from $r$ families of axis-parallel boxes in $R^{d}$ with prescribed direction…

math.CO2025

Set families: restricted distances via restricted intersections

Zichao Dong, Jun Gao, Hong Liu +2

Denote by $f_{D} (n)$ the maximum size of a set family $F$ on $[n] \stackrel{\mbox{\normalfont\tiny def}}{=} \{1, \dots, n\}$ with distance set $D$ . That is, $|A \bigtriangl…

math.CO2025

Bipartite TurÃ¡n problems via graph gluing

Zichao Dong, Jun Gao, Hong Liu

For graphs $H_{1}$ and $H_{2}$ , if we glue them by identifying a given pair of vertices $u \in V (H_{1})$ and $v \in V (H_{2})$ , what is the extremal number of the resulting graph $H_1^u \od…

math.CO2025

Saturation results around the ErdÅs--Szekeres problem

GÃ¡bor DamÃ¡sdi, Zichao Dong, Manfred Scheucher +1

In this paper, we consider saturation problems related to the celebrated ErdÅs--Szekeres convex polygon problem. For each $n \geq 7$ , we construct a planar point set of size $(7/8)…

math.CO2025

Large grid subsets without many cospherical points

Zichao Dong, Zijian Xu

Motivated by intuitions from projective algebraic geometry, we provide a novel construction of subsets of the $d$ -dimensional grid $[n]^{d}$ of size $n - o (n)$ with no $d + 2$ points…

Sharp bounds on k-wise generalizations of oddtowns and eventowns

A dichotomy for hypergraph Zarankiewicz problems on axis-parallel boxes

Set families: restricted distances via restricted intersections

Bipartite TurÃ¡n problems via graph gluing

Saturation results around the ErdÅs--Szekeres problem

Large grid subsets without many cospherical points

Sharp bounds on $k$ -wise generalizations of oddtowns and eventowns

Saturation results around the ErdÅs--Szekeres problem