Weijun Liu

activity

20192025

most citedA new matrix inequality involving partial traces

4 citations · 9 across the 16 of their papers we have counts for

collaborators

19 papers

math.GR2025

Large maximal subgroups of almost simple classical groups

Fu-Gang Yin, Ting Lan, Weijun Liu +1

A proper subgroup $H$ of a finite group $G$ is called large if $|H|^3 \ge |G|$. This paper characterises all the large maximal subgroups of almost simple groups whose socle i…

math.GR2025

The Terwilliger algebras of the group association schemes of non-abelian finite groups admitting an abelian subgroup of index 2

Jing Yang, Qinghong Guo, Weijun Liu +1

In this paper, we determine the dimension of the Terwilliger algebras of non-abelian finite groups admitting an abelian subgroup of index 2 by showing that they are triply transiti…

math.GR2024

On biprimitive semisymmetric graphs

Yunsong Gan, Weijun Liu, Binzhou Xia

A regular bipartite graph $Γ$ is called semisymmetric if its full automorphism group $Aut (Γ)$ acts transitively on the edge set but not on the vertex set. For a subgroup $…

math.CO2024

Generalized Cayley graphs of complete groups

Qianfen Liao, Liu Weijun

A group $G$ is complete group if it satisfies $Z (G) = e$ and $A u t (G) = I nn (G)$ . In this paper, on the one hand, we study the basic properties of generalized Cayley graphs and character…

math.CO2024

Generalized Cayley graphs and perfect code

Liao Qianfen, Liu Weijun

Perfect code in Cayley graphs and Cayley sum graphs is studied extensively in recent years. In this paper, we consider perfect code in generalized Cayley graphs.

math.CO2023

Some properties of generalized Cayley graphs

Liao Qianfen, Liu Weijun, Zhang Pengli

In this paper, firstly, we provide some necessary and sufficient conditions for generalized Cayley graphs on abelian groups to be bipartite. Secondly, we deduce several necessary a…

math.CO2023

Block-transitive $3$ - $(v, k, 1)$ designs on exceptional groups of Lie type

Ting Lan, Weijun Liu, Fu-Gang Yin

Let $D$ be a non-trivial $G$ -block-transitive $3$ - $(v, k, 1)$ design, where $T \leq G \leq Aut (T)$ for some finite non-abelian simple group $T$ . It is proved that i…

math.GR2022

Block-transitive $3$ - $(v, k, 1)$ designs associated with alternating groups

Ting Lan, Weijun Liu, Fu-Gang Yin

Let $D$ be a nontrivial $3$ - $(v, k, 1)$ design admitting a block-transitive group $G$ of automorphisms. A recent work of Gan and the second author asserts that $G$ is eithe…

math.CO2022

Spectral radius and the $2$ -power of Hamilton cycles

Xinru Yan, Xiaocong He, Lihua Feng +1

Let $G$ be a graph of order $n$ and spectral radius be the largest eigenvalue of its adjacency matrix, denoted by $μ (G)$ . In this paper, we determine the unique graph with maximum…

math.CO2021

A survey on spectral conditions for some extremal graph problems

Yongtao Li, Weijun Liu, Lihua Feng

This survey is two-fold. We first report new progress on the spectral extremal results on the Turán type problems in graph theory. More precisely, we shall summarize the spectral T…

math.CO2021

The Q-index and connectivity of graphs

Peng-Li Zhang, Lihua Feng, Weijun Liu +1

A connected graph $G$ is said to be $k$ -connected if it has more than $k$ vertices and remains connected whenever fewer than $k$ vertices are deleted. In this paper, for a connecte…

math.CO2021★ 1 cited

A tight $Q$ -index condition for a graph to be $k$ -path-coverable involving minimum degree

Tao Cheng, Lihua Feng, Yongtao Li +1

A graph $G$ is $k$ -path-coverable if its vertex set $V (G)$ can be covered by $k$ or fewer vertex disjoint paths. In this paper, using the $Q$ -index of a connected graph $G$ , we pre…

math.FA2020

Inequalities for generalized matrix function and inner product

Yang Huang, Yongtao Li, Lihua Feng +1

We present inequalities related to generalized matrix function for positive semidefinite block matrices. We introduce partial generalized matrix functions corresponding to partial…

math.RA2020

Extensions of Fiedler-Markham's inequality and Thompson's inequality

Yongtao Li, Yang Huang, Lihua Feng +1

We present some new inequalities related to determinant and trace for positive semidefinite block matrices by using symmetric tensor product, which are extensions of Fiedler-Markha…

math.FA2020

Another determinantal inequality involving partial traces

Yongtao Li, Lihua Feng, Weijun Liu +1

Let $A$ be a positive semidefinite $m \times m$ block matrix with each block $n$ -square, then the following determinantal inequality for partial traces holds \[ (\mathrm{tr} A)^{mn}…

math.FA2020★ 2 cited

Extensions of Brunn-Minkovski's inequality to multiple matrices

Yongtao Li, Lihua Feng

Yuan and Leng (2007) gave a generalization of Ky Fan's determinantal inequality, which is a celebrated refinement of the fundamental Brunn-Minkowski inequality $(\det (A+B))^{1/n}…

math.FA2020★ 4 cited

A new matrix inequality involving partial traces

Yongtao Li, Weijun Liu, Yang Huang

Let $A$ be an $m \times m$ positive semidefinite block matrix with each block being $n$ -square. We write $tr_{1}$ and $tr_{2}$ for the first and second partial trace,…

math.FA2020★ 2 cited

Some applications of two completely copositive maps

Yongtao Li, Yang Huang, Lihua Feng +1

A linear map $Φ : M_{n} \to M_{k}$ is called completely copositive if the resulting matrix $[Φ (A_{j, i})]_{i, j = 1}^{m}$ is positive semidefinite for any integer $m$ and pos…

math.RT2019

Some properties for morphism of representations

Yang Huang, Yongtao Li, Weijun Liu +1

Let $ψ : G \to G L (V)$ and $φ : G \to G L (W)$ be representations of finite group $G$ . A linear map $T : V \to W$ is called a morphism from $ψ$ to $φ$ if it satisfys $T ψ_{g} = φ_{g} T$ for each…