Ji Zeng

activity

20232026

collaborators

16 papers

math.CO2026

Compactness of abundance in asymmetric hypergraph removal lemmas

Shuang Sun, Yan Wang, Yuyao Yang +1

Fix an integer $r \geq 2$ and a finite simple $r$ -uniform hypergraph $F$ with at least one edge and no isolated vertices. An $n$ -vertex $r$ -graph is $ε$ -far from being $F$ -free if at…

math.CO2026

Asymptotic Uniformity of Permanents of Random Matrices over Finite Fields of Odd Characteristic

Shuang Sun, Yuyao Yang, Jiasheng Zeng

Let $q$ be an odd prime power, and let $A_{n} = (a_{ij}) \in F_{q}^{n \times n}$ be a random matrix whose entries are independent and uniformly distributed on $F_{q}$ . The per…

math.CO2026

Every fork-free graph is perfectly weight divisible

Feng Liu, Shuang Sun, Yan Wang +2

A graph $G$ is \emph{perfectly weight divisible} if, for every positive integral weight function on $V (G)$ and every induced subgraph $H$ of $G$ with at least one edge, the vertex…

math.CO2026

A Single-Exponential Erdős--Hajnal Bound for Graphs of Bounded VC-Dimension

Shuang Sun, Yan Wang, Jiasheng Zeng

A homogeneous set in a graph is a clique or a stable set. The Erdős--Hajnal conjecture states that, for every graph $H$ , there exists $c > 0$ such that every $H$ -free graph on $n$ ve…

math.CO2026

Finite-Kernel Extremizers in Sparse Extremal Graph Counting

Jiasheng Zeng

We develop a finite-kernel framework for sparse extremal graph counting. The problems considered here ask for the maximum number of copies or homomorphisms of a fixed graph under s…

math.CO2026

Proofs of Two Conjectures of Alon on Subgraph Counts

Peiru Kuang, Shuang Sun, Yan Wang +1

All graphs considered are finite with no isolated vertices. Let $N (m, H)$ be the maximum number of subgraphs of a graph $G$ isomorphic to $H$ , taken over all graphs $G$ with $m$ edg…

math.CO2026

Sharp Bounds for Guiduli-Type Hereditary Spectral Problems

Dongxiu Cai, Jiasheng Zeng, Xiao-Dong Zhang

Guiduli asked in 1996 the following problem concerning the maximum spectral radius of a graph under hereditary density constraints. If an $n$ -vertex graph $G$ satisfies $e(H)\le c|…

math.CO2026

Tight Bound for Nikiforov's Spectral Even-Cycle Conjecture

Peiru Kuang, Feng Liu, Shuang Sun +2

Nikiforov conjectured that, for every fixed $k \geq 2$ and all sufficiently large $n$ , the unique $n$ -vertex $C_{2 k + 2}$ -free graph with maximum adjacency spectral radius is $S^+_{n,k}…

math.CO2026

Polylogarithmic Bounds for Nested Cycles without Geometric Crossings

Yue Xu, Jiasheng Zeng, Xiao-Dong Zhang

A problem of Erdős asks for extremal conditions forcing edge-disjoint cycles with a prescribed nested structure. In the geometric version, the nesting is required to be noncrossing…

math.CO2026

A note on the $t$ -partite link problem of Füredi

Jianfeng Hou, Xinmin Hou, Xizhi Liu +2

Motivated by the Erdős--Sós bipartite link conjecture, Füredi (Oberwolfach, 2004) asked for the asymptotic maximum edge density $π_{link} (t)$ of $3$ -graphs in which the li…

math.CO2026

On the $(k + 2, k)$ -problem of Brown, Erdős and Sós for even integers $k$

Yan Wang, Jiasheng Zeng

Let $f^{(r)} (n; s, k)$ denote the maximum number of edges in an $r$ -graph on $n$ vertices in which every $k$ edges span more than $s$ vertices. Brown, Erdős and Sós in 1973 conjectur…

math.CO2026

On the Borodin--Kostochka conjecture for graphs with large maximum degree

Feng Liu, Shuang Sun, Yan Wang +1

The Borodin--Kostochka conjecture states that every graph $G$ with maximum degree $Δ (G) \geq 9$ satisfies $χ (G) \leq max {ω (G), Δ (G) - 1}$ . In this paper, we verify this conjecture for…

math.CO2025

Unavoidable patterns and plane paths in dense topological graphs

Balázs Keszegh, Andrew Suk, Gábor Tardos +1

Let $C_{s, t}$ be the complete bipartite geometric graph, with $s$ and $t$ vertices on two distinct parallel lines respectively, and all $s t$ straight-line edges drawn between them…

math.CO2024

3-uniform monotone paths and multicolor Ramsey numbers

Andrew Suk, Ji Zeng

The monotone path $P_{n + 2}$ is an ordered 3-uniform hypergraph whose vertex set has size $n + 2$ and edge set consists of all consecutive triples. In this note, we consider the colle…

math.CO2023

On cliques in three-dimensional dense point-line arrangements

Andrew Suk, Ji Zeng

As a variant of the celebrated Szemerédi--Trotter theorem, Guth and Katz proved that $m$ points and $n$ lines in $R^{3}$ with at most $n$ lines in a common plane must…

math.CO2023

Random Turán and counting results for general position sets over finite fields

Yaobin Chen, Xizhi Liu, Jiaxi Nie +1

Let $α (F_{q}^{d}, p)$ denote the maximum size of a general position set in a $p$ -random subset of $F_{q}^{d}$ . We determine the order of magnitude of $α (F_{q}^{2}, p)$ …

Compactness of abundance in asymmetric hypergraph removal lemmas

Asymptotic Uniformity of Permanents of Random Matrices over Finite Fields of Odd Characteristic

Every fork-free graph is perfectly weight divisible

A Single-Exponential Erdős--Hajnal Bound for Graphs of Bounded VC-Dimension

Finite-Kernel Extremizers in Sparse Extremal Graph Counting

Proofs of Two Conjectures of Alon on Subgraph Counts

Sharp Bounds for Guiduli-Type Hereditary Spectral Problems

Tight Bound for Nikiforov's Spectral Even-Cycle Conjecture

Polylogarithmic Bounds for Nested Cycles without Geometric Crossings

A note on the t-partite link problem of Füredi

On the (k+2,k)-problem of Brown, Erdős and Sós for even integers k

On the Borodin--Kostochka conjecture for graphs with large maximum degree

Unavoidable patterns and plane paths in dense topological graphs

3-uniform monotone paths and multicolor Ramsey numbers

On cliques in three-dimensional dense point-line arrangements

Random Turán and counting results for general position sets over finite fields

A note on the $t$ -partite link problem of Füredi

On the $(k + 2, k)$ -problem of Brown, Erdős and Sós for even integers $k$