Xiuwen Yang

activity

20202026

collaborators

4 papers

math.CO2026

Extremal Laplacian energy of $C_{k + 1}$ -free digraphs

Xiuwen Yang, Lin-Peng Zhang

The Laplacian energy of a digraph $G$ is defined as $\sum_{i = 1}^{n} λ_{i}^{2}$ , where $λ_{i}$ are the eigenvalues of the Laplacian matrix of $G$ . A (di)graph $G$ is said to be $H$ -free if…

math.CO2023

Sharp bounds for Laplacian spectral moments of digraphs with a fixed dichromatic number

Xiuwen Yang, Hajo Broersma, Ligong Wang

The $k$ -th Laplacian spectral moment of a digraph $G$ is defined as $\sum_{i = 1}^{n} λ_{i}^{k}$ , where $λ_{i}$ are the eigenvalues of the Laplacian matrix of $G$ and $k$ is a nonnegative in…

math.CO2021

On the $A_{α}$ spectral radius and $A_{α}$ energy of non-strongly connected digraphs

Xiuwen Yang, Ligong Wang

Let $A_{α} (G)$ be the $A_{α}$ -matrix of a digraph $G$ and $λ_{α 1}, λ_{α 2}, \dots, λ_{α n}$ be the eigenvalues of $A_{α} (G)$ . Let $ρ_{α} (G)$ be the $A_{α}$ spectral radius of $G$ and $E_α(G)=…

math.CO2020

Iota energy orderings of bicyclic signed digraphs

Xiuwen Yang, Ligong Wang

The concept of energy of a signed digraph is extended to iota energy of a signed digraph. The energy of a signed digraph $S$ is defined by $E (S) = \sum_{k = 1}^{n} ∣ Re (z_{k}) ∣$ , wher…

Extremal Laplacian energy of Ck+1​​-free digraphs

Sharp bounds for Laplacian spectral moments of digraphs with a fixed dichromatic number

On the Aα​ spectral radius and Aα​ energy of non-strongly connected digraphs

Iota energy orderings of bicyclic signed digraphs

Extremal Laplacian energy of $C_{k + 1}$ -free digraphs

On the $A_{α}$ spectral radius and $A_{α}$ energy of non-strongly connected digraphs