Yong Lu

activity

20172026

most citedThe rank of a complex unit gain graph in terms of the rank of its underlying graph

1 citations · 1 across the 8 of their papers we have counts for

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math.CO2026

Hamiltonian cycles in 7-tough $(P_{4} \cup P_{1})$ -free graphs

Yong Lu, Qi Wu, Qiannan Zhou

Shan~[J. Graph Theory (2026)] proved that every 23-tough $(P_{4} \cup P_{1})$ -free graph on at least three vertices is Hamiltonian. We improve this bound to 7 by replacing the final cut…

math.CO2025

Distance signless Laplacian spectral radius and tough graphs involving minimun degree

Xiangge Liu, Yong Lu, Caili Jia +2

Let $G = (V (G), E (G))$ be a simple graph, where $V (G)$ and $E (G)$ are the vertex set and the edge set of $G$ , respectively. The number of components of $G$ is denoted by $c (G)$ . Let $…

math.CO2021

The rank of a signed graph in terms of girth

Yong Lu, Qi Wu

Let $Γ = (G, σ)$ be a signed graph and $A (G, σ)$ be its adjacency matrix. Denote by $g r (G)$ the girth of $G$ , which is the length of the shortest cycle in $G$ . Let $r (G, σ)$ be the rank…

math.CO2021

Inertia indices of a complex unit gain graph in terms of matching number

Yong Lu, Qi Wu

A complex unit gain graph is a triple $φ = (G, T, φ)$ (or $G^{φ}$ for short) consisting of a simple graph $G$ , as the underlying graph of $G^{φ}$ , the set of unit complex number…

math.CO2020

No signed graph with the nullity $η (G, σ) = ∣ V (G) ∣ - 2 m (G) + 2 c (G) - 1$

Yong Lu, Jingwen Wu

Let $G^{σ} = (G, σ)$ be a signed graph and $A (G, σ)$ be its adjacency matrix. Denote by $m (G)$ the matching number of $G$ . Let $η (G, σ)$ be the nullity of $(G, σ)$ . He et al. [Bounds for t…

math.CO2017

Signless Laplacian spectral conditions for Hamilton-connected graphs with large minimum degree

Qiannan Zhou, Ligong Wang, Yong Lu

In this paper, we present a spectral sufficient condition for a graph to be Hamilton-connected in terms of signless Laplacian spectral radius with large minimum degree.

Hamiltonian cycles in 7-tough (P4​∪P1​)-free graphs