activity
20192026
most citedOn Hamiltonian Berge cycles in -uniform hypergraphs

3 citations · 3 across the 12 of their papers we have counts for

collaborators

12 papers

math.CO2026

On the classification of regular graphs with positive Lin-Lu-Yau curvature

George Brooks, Nathanael Johnson, William Linz +3

We prove several new structural and classification results about -regular graphs with positive Lin--Lu--Yau (LLY) curvature. We show that any positively curved -regular graph…

math.CO2026

Maximum spread of -minor-free graphs II: the non-admissible cases

William Linz, Linyuan Lu, Zhiyu Wang

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

math.CO2026

Generalized Nordhaus--Gaddum Inequalities for Eigenvalues

Sahil Agarwal, Carter Antley, Joseph Aulenbacher +6

For a graph , let denote the adjacency eigenvalues of . We prove that for all looped graphs on vertices, \[λ_1(G) + λ_2(\over…

math.CO2026

Turán-Type Bounds for Graphs Containing Large -Sparse Sets

Yupei Li, Linyuan Lu

We study Turán-type extremal problems for graphs containing a large -sparse vertex set, meaning a vertex set whose induced subgraph contains few copies of . For integers $r>s…

math.CO2025

An Ore-type theorem for -graphs

Yupei Li, Linyuan Lu, Ruth Luo

Ore's Theorem states that if is an -vertex graph and every pair of non-adjacent vertices has degree sum at least , then is Hamiltonian. A -graph is a hypergraph…

math.CO2024

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

Xiaonan Liu, Linyuan Lu, Zhiyu Wang

In this paper, extending a result of Brooks et.al. [arXiv:2403.04110], we show that if an outerplanar graph with minimum degree at least has positive Lin-Lu-Yau curvature o…

math.CO2024

Ricci Curvature Formula: Applications to Bonnet-Myers Sharp Irregular Graphs

Yupei Li, Linyuan Lu

In this paper, we establish a simple formula for computing the Lin-Lu-Yau Ricci curvature on graphs. For any edge in a simple locally finite graph , the curvature …

math.CO2024

Maximum spectral gaps of graphs

George Brooks, William Linz, Linyuan Lu

The spread of a graph is the difference between the largest and smallest eigenvalues of its adjacency matrix. Breen, Riasanovsky, Tait and Urschel recently determin…

math.CO2024

Maximum spread of -minor-free graphs

William Linz, Linyuan Lu, Zhiyu Wang

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

math.CO2023

A tight bound on -free connected graphs with positive Lin-Lu-Yau Ricci curvature

E. G. K. M. Gamlath, Xiaonan Liu, Linyuan Lu +1

In this paper, we prove that any simple -free non-empty connected graph with LLY curvature bounded below by has the order at most . This upper…

math.CO2023

On the maximum second eigenvalue of outerplanar graphs

George Brooks, Maggie Gu, Jack Hyatt +2

For a fixed positive integer and a graph , let denote the -th largest eigenvalue of the adjacency matrix of . In 2017, Tait and Tobin proved that the maximum…

math.CO2019★ 3 cited

On Hamiltonian Berge cycles in -uniform hypergraphs

Linyuan Lu, Zhiyu Wang

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