Weige Xi

activity

20162026

most citedMerging the A- and Q-spectral theories for digraphs

3 citations · 4 across the 14 of their papers we have counts for

collaborators

14 papers

math.CO2026

Spectral extremal problems for fractional $I D$ - $[a, b]$ -factor-critical graphs

Zengzhao Xu, Ligong Wang, Weige Xi

A factor of a graph is essentially a specific type spanning subgraph. In recent years, the spectral extremal problem of characterizing the existence of graph factors via eigenvalue…

math.CO2025

Spectral extremal problems for $(a, b, k)$ -critical and fractional $(a, b, k)$ -critical graphs

Zengzhao Xu, Ligong Wang, Weige Xi

A factor of a graph is essentially a specific type spanning subgraph. The study of characterizing the existence of $[a, b]$ -factors based on eigenvalue conditions can be traced bac…

math.CO2025

Spectral radius and size conditions for fractional $(a, b, m)$ -covered graphs

Zengzhao Xu, Ligong Wang, Weige Xi

A fractional $(a, b, m)$ -covered graph is a generalization of the concept of a fractional $[a, b]$ -covered graph. For any $H \subseteq G$ with edge set $∣ E (H) ∣ = m$ , if there exists a…

math.CO2025

Ordering digraphs with maximum outdegrees by their $A_{α}$ spectral radius

Zengzhao Xu, Weige Xi, Ligong Wang

Let $G$ be a strongly connected digraph with $n$ vertices and $m$ arcs. For any real $α \in [0, 1]$ , the $A_{α}$ matrix of a digraph $G$ is defined as $A_{α} (G) = α D (G) + (1 - α) A (G),$ where…

math.CO2024

On the $D_{α}$ spectral radius of non-transmission regular graphs

Zengzhao Xu, Weige Xi, Ligong Wang

Let $G$ be a connected graph with order $n$ and size $m$ . Let $D (G)$ and $T r (G)$ be the distance matrix and diagonal matrix with vertex transmissions of $G$ , respectively. For any…

math.CO2024

Matching, odd $[1, b]$ -factor and distance spectral radius of graphs with given some parameters

Zengzhao Xu, Weige Xi, Ligong Wang

For a connected graph $G$ , let $μ (G)$ denote the distance spectral radius of $G$ . A matching in a graph $G$ is a set of disjoint edges of $G$ . The maximum size of a matching in $G$ …

math.CO2023

On the distance spectral radius, fractional matching and factors of graphs with given minimum degree

Zengzhao Xu, Weige Xi, Ligong Wang

A fractional matching of $G$ is a function $f : E (G) \to [0, 1]$ such that $\sum_{e \in E_{G} (v_{i})} f (e) \leq 1$ for any $v_{i} \in V (G)$ , where $E_G(v_i)=\{e: e\in E(G) \ \textrm{and}\ e \ \t…

math.CO2021★ 1 cited

On the $A_{α}$ spectral radius and $A_{α}$ energy of digraphs

Weige Xi

Let $G$ be a digraph with adjacency matrix $A (G)$ and outdegrees diagonal matrix $D (G)$ . For any real $α \in [0, 1]$ , the $A_{α}$ matrix $A_{α} (G)$ of a digraph $G$ is defined as $A_α(G)=…

math.CO2021

On the $A_{α}$ spectral radius of strongly connected digraphs

Weige Xi, Ligong Wang

Let $G$ be a digraph with adjacency matrix $A (G)$ . Let $D (G)$ be the diagonal matrix with outdegrees of vertices of $G$ . Nikiforov \cite{Niki} proposed to study the convex combinat…

math.CO2018

The generalized distance matrix of digraphs

Weige Xi, Wasin So, Ligong Wang

Let $D (G)$ and $D^{Q} (G) = D ia g (T r) + D (G)$ be the distance matrix and distance signless Laplacian matrix of a simple strongly connected digraph $G$ , respectively, where $Diag(Tr)=\te…

math.CO2018★ 3 cited

Merging the A- and Q-spectral theories for digraphs

Weige Xi, Wasin So, Ligong Wang

Let $G$ be a digraph and $A (G)$ be the adjacency matrix of $G$ . Let $D (G)$ be the diagonal matrix with outdegrees of vertices of $G$ . For any real $α \in [0, 1]$ , Liu et al. \cite{LWC…

math.CO2018

The unicyclic graphs with the second smallest normalized Laplacian eigenvalue no less than $1 - \frac{6}{3}$

Weige Xi, Ligong Wang, Xiangxiang Liu +2

Let $λ_{2} (G)$ be the second smallest normalized Laplacian eigenvalue of a graph $G$ . In this paper, we determine all unicyclic graphs of order $n \geq 21$ with $λ_{2}(G)\geq 1-\frac…

math.CO2017

The minimum Q-index of strongly connected bipartite digraphs with complete bipartite subdigraphs

Weige Xi, Ligong Wang

Let $G_{n, p, q}$ denote the set of strongly connected bipartite digraphs on $n$ vertices which contain a complete bipartite subdigraph $K_{p, q}$ , wher…

math.CO2016

Some upper bounds for the signless Laplacian spectral radius of digraphs

Weige Xi, Ligong Wang

Let $G = (V (G), E (G))$ be a digraph without loops and multiarcs, where $V (G) = {v_{1}, v_{2}, \dots, v_{n}}$ and $E (G)$ are the vertex set and the arc set of $G$ , respectively. Let $d_{i}^{+}$ …

Spectral extremal problems for fractional ID-[a,b]-factor-critical graphs

Spectral extremal problems for (a,b,k)-critical and fractional (a,b,k)-critical graphs

Spectral radius and size conditions for fractional (a,b,m)-covered graphs

Ordering digraphs with maximum outdegrees by their Aα​ spectral radius

On the Dα​ spectral radius of non-transmission regular graphs

Matching, odd [1,b]-factor and distance spectral radius of graphs with given some parameters

On the distance spectral radius, fractional matching and factors of graphs with given minimum degree

On the Aα​ spectral radius and Aα​ energy of digraphs

On the Aα​ spectral radius of strongly connected digraphs

The generalized distance matrix of digraphs

Merging the A- and Q-spectral theories for digraphs

The unicyclic graphs with the second smallest normalized Laplacian eigenvalue no less than 1−36​​

The minimum Q-index of strongly connected bipartite digraphs with complete bipartite subdigraphs

Some upper bounds for the signless Laplacian spectral radius of digraphs

Spectral extremal problems for fractional $I D$ - $[a, b]$ -factor-critical graphs

Spectral extremal problems for $(a, b, k)$ -critical and fractional $(a, b, k)$ -critical graphs

Spectral radius and size conditions for fractional $(a, b, m)$ -covered graphs

Ordering digraphs with maximum outdegrees by their $A_{α}$ spectral radius

On the $D_{α}$ spectral radius of non-transmission regular graphs

Matching, odd $[1, b]$ -factor and distance spectral radius of graphs with given some parameters

On the $A_{α}$ spectral radius and $A_{α}$ energy of digraphs

On the $A_{α}$ spectral radius of strongly connected digraphs

The unicyclic graphs with the second smallest normalized Laplacian eigenvalue no less than $1 - \frac{6}{3}$