Zhiyu Wang

activity

20172026

most citedOn difference graphs and the local dimension of posets

12 citations · 35 across the 28 of their papers we have counts for

collaborators

31 papers

math.CO2026

Toughness Bounds for Fractional Hamiltonicity and Resistance Positivity

Zhiyu Wang

A graph is fractionally Hamiltonian if it admits a nonnegative edge weighting in $[0, 1]$ of total weight equal to its order such that every nontrivial edge cut has weight at least…

math.CO2026

Perfect Divisibility, Linear Divisibility and Chair-Free Graphs

Zhiyu Wang, Weihao Xia

A graph is perfectly divisible if every induced subgraph with at least one edge admits a partition into a perfect induced subgraph and an induced subgraph with smaller clique numbe…

math.CO2026

On some structural properties of graphs with non-negative resistance curvature

Gyaneshwar Agrahari, Christin Bibby, Sean Boros +4

A graph is called resistance nonnegative (RN), respectively resistance positive (RP), if it admits positive edge weights such that all vertex resistance curvatures are nonnegative,…

math.CO2026

Maximum spread of $K_{s, t}$ -minor-free graphs II: the non-admissible cases

William Linz, Linyuan Lu, Zhiyu Wang

We have previously determined the maximum-spread $K_{s, t}$ -minor-free graph(s) on $n$ vertices when $n$ is sufficiently large, $2 \leq s \leq t$ , and $s = 2$ or $t\ge \frac{3}{2}(s-3) +…

math.CO2024

Maximum spread of $K_{s, t}$ -minor-free graphs

William Linz, Linyuan Lu, Zhiyu Wang

The spread of a graph $G$ is the difference between the largest and smallest eigenvalue of the adjacency matrix of $G$ . In this paper, we consider the family of graphs which contai…

math.CO2022★ 1 cited

Maximum spread of $K_{2, t}$ -minor-free graphs

William Linz, Linyuan Lu, Zhiyu Wang

The spread of a graph $G$ is the difference between the largest and smallest eigenvalues of the adjacency matrix of $G$ . In this paper, we consider the family of graphs which conta…

math.CO2022

On the maximum spread of planar and outerplanar graphs

Zelong Li, William Linz, Linyuan Lu +1

The spread of a graph $G$ is the difference between the largest and smallest eigenvalue of the adjacency matrix of $G$ . Gotshall, O'Brien and Tait conjectured that for sufficiently…

math.CO2021

On the 3-colorability of triangle-free and fork-free graphs

Joshua Schroeder, Zhiyu Wang, Xingxing Yu

A graph $G$ is said to satisfy the Vizing bound if $χ (G) \leq ω (G) + 1$ , where $χ (G)$ and $ω (G)$ denote the chromatic number and clique number of $G$ , respectively. It was conjectured…

math.CO2021★ 3 cited

Polynomial $χ$ -binding functions for $t$ -broom-free graphs

Xiaonan Liu, Joshua Schroeder, Zhiyu Wang +1

For any positive integer $t$ , a \emph{ $t$ -broom} is a graph obtained from $K_{1, t + 1}$ by subdividing an edge once. In this paper, we show that, for graphs $G$ without induced $t$ -b…

math.CO2021

Counting Hamiltonian cycles in planar triangulations

Xiaonan Liu, Zhiyu Wang, Xingxing Yu

Hakimi, Schmeichel, and Thomassen in 1979 conjectured that every $4$ -connected planar triangulation $G$ on $n$ vertices has at least $2 (n - 2) (n - 4)$ Hamiltonian cycles, with equality…

math.CO2021★ 1 cited

Anti-Ramsey number of edge-disjoint rainbow spanning trees in all graphs

Linyuan Lu, Andrew Meier, Zhiyu Wang

An edge-colored graph $G$ is called \textit{rainbow} if every edge of $G$ receives a different color. Given any host graph $G$ , the \textit{anti-Ramsey} number of $t$ edge-disjoint…

math.CO2020

On the size of planar graphs with positive Lin-Lu-Yau Ricci curvature

Linyuan Lu, Zhiyu Wang

We show that if a planar graph $G$ with minimum degree at least $3$ has positive Lin-Lu-Yau Ricci curvature on every edge, then $Δ (G) \leq 17$ , which then implies that $G$ is finite…

math.CO2020

Maximum spectral radius of outerplanar 3-uniform hypergraphs

M. N. Ellingham, Linyuan Lu, Zhiyu Wang

In this paper, we study the maximum spectral radius of outerplanar $3$ -uniform hypergraphs. Given a hypergraph $H$ , the shadow of $H$ is a graph $G$ with $V(G)=…

math.DG2020★ 2 cited

Ollivier Ricci-flow on weighted graphs

Shuliang Bai, Yong Lin, Linyuan Lu +2

We study the existence of solutions of Ricci flow equations of Ollivier-Lin-Lu-Yau curvature defined on weighted graphs. Our work is motivated by\cite{NLLG} in which the discrete t…

math.CO2020

Saturation problems in the Ramsey theory of graphs, posets and point sets

Gábor Damásdi, Balázs Keszegh, David Malec +3

In 1964, Erdős, Hajnal and Moon introduced a saturation version of Turán's classical theorem in extremal graph theory. In particular, they determined the minimum number of edges in…

math.CO2019

Some remarks on the midrange crossing constant

É. Czabarka, I. Singgih, L. A. Székely +1

We verify an upper bound of Pach and Tóth [Combinatorica 17(1997), 427-439, Discrete and Computational Geometry 36(2006), 527-552] on the midrange crossing constant. Details of the…

math.CO2019

Concentration inequalities in spaces of random configurations with positive Ricci curvatures

Linyuan Lu, Zhiyu Wang

In this paper, we prove an Azuma-Hoeffding-type inequality in several classical models of random configurations, including the Erdős-Rényi random graph models $G (n, p)$ and $G (n, M)$ …

math.CO2019

On the cover Turán number of Berge hypergraphs

Linyuan Lu, Zhiyu Wang

For a fixed set of positive integers $R$ , we say $H$ is an $R$ -uniform hypergraph, or $R$ -graph, if the cardinality of each edge belongs to $R$ . For a graph $G = (V, E)$ , a…

math.CO2019★ 1 cited

On the cover Ramsey number of Berge hypergraphs

Linyuan Lu, Zhiyu Wang

For a fixed set of positive integers $R$ , we say $H$ is an $R$ -uniform hypergraph, or $R$ -graph, if the cardinality of each edge belongs to $R$ . An $R$ -graph $\mathcal{H}…

math.CO2019★ 3 cited

On Hamiltonian Berge cycles in $3$ -uniform hypergraphs

Linyuan Lu, Zhiyu Wang

Given a set $R$ , a hypergraph is $R$ -uniform if the size of every hyperedge belongs to $R$ . A hypergraph $H$ is called \textit{covering} if every vertex pair is contained…

math.CO2018★ 2 cited

The extremal $p$ -spectral radius of Berge-hypergraphs

Liying Kang, Lele Liu, Linyuan Lu +1

Let $G$ be a graph. We say that a hypergraph $H$ is a Berge- $G$ if there is a bijection $ϕ : E (G) \to E (H)$ such that $e \subseteq ϕ (e)$ for all $e \in E (G)$ . For any $r$ -uniform hyper…

cs.DS2018

On a hypergraph probabilistic graphical model

Mohammad Ali Javidian, Linyuan Lu, Marco Valtorta +1

We propose a directed acyclic hypergraph framework for a probabilistic graphical model that we call Bayesian hypergraphs. The space of directed acyclic hypergraphs is much larger t…

math.CO2018

Midrange crossing constants for graphs classes

Éva Czabarka, Josiah Reiswig, László Székely +1

For positive integers $n$ and $e$ , let $κ (n, e)$ be the minimum crossing number (the standard planar crossing number) taken over all graphs with $n$ vertices and at least $e$ edges.…

math.CO2018

Ramsey numbers of Berge-hypergraphs and related structures

Nika Salia, Casey Tompkins, Zhiyu Wang +1

For a graph $G = (V, E)$ , a hypergraph $H$ is called a Berge- $G$ , denoted by $B G$ , if there exists a bijection $f : E (G) \to E (H)$ such that for every $e \in E (G)$ ,…

Toughness Bounds for Fractional Hamiltonicity and Resistance Positivity

Perfect Divisibility, Linear Divisibility and Chair-Free Graphs

On some structural properties of graphs with non-negative resistance curvature

Maximum spread of Ks,t​-minor-free graphs II: the non-admissible cases

Maximum spread of Ks,t​-minor-free graphs

Maximum spread of K2,t​-minor-free graphs

On the maximum spread of planar and outerplanar graphs

On the 3-colorability of triangle-free and fork-free graphs

Polynomial χ-binding functions for t-broom-free graphs

Counting Hamiltonian cycles in planar triangulations

Anti-Ramsey number of edge-disjoint rainbow spanning trees in all graphs

On the size of planar graphs with positive Lin-Lu-Yau Ricci curvature

Maximum spectral radius of outerplanar 3-uniform hypergraphs

Ollivier Ricci-flow on weighted graphs

Saturation problems in the Ramsey theory of graphs, posets and point sets

Some remarks on the midrange crossing constant

Concentration inequalities in spaces of random configurations with positive Ricci curvatures

On the cover Turán number of Berge hypergraphs

On the cover Ramsey number of Berge hypergraphs

On Hamiltonian Berge cycles in 3-uniform hypergraphs

The extremal p-spectral radius of Berge-hypergraphs

On a hypergraph probabilistic graphical model

Midrange crossing constants for graphs classes

Ramsey numbers of Berge-hypergraphs and related structures

Maximum spread of $K_{s, t}$ -minor-free graphs II: the non-admissible cases

Maximum spread of $K_{s, t}$ -minor-free graphs

Maximum spread of $K_{2, t}$ -minor-free graphs

Polynomial $χ$ -binding functions for $t$ -broom-free graphs

On Hamiltonian Berge cycles in $3$ -uniform hypergraphs

The extremal $p$ -spectral radius of Berge-hypergraphs