Zhuang Xiong

collaborators

4 papers

math.CO2023

Extremal results for $K_{r + 1}^{-}$ -free signed graphs

Zhuang Xiong, Yaoping Hou

This paper gives tight upper bounds on the number of edges and the index for $K_{r + 1}^{-}$ -free unbalanced signed graphs, where $K_{r + 1}^{-}$ is the set of $r+1…

math.CO2023

Maxima of the index: forbidden unbalanced cycles

Zhuang Xiong, Yaoping Hou

This paper aims to address the problem: what is the maximum index among all $C_{r}^{-}$ -free unbalanced signed graphs, where $C_{r}^{-}$ is the set of unbalanced cycle…

math.CO2023

On the eigenvalues and Seidel eigenvalues of chain graphs

Zhuang Xiong, Yaoping Hou

In this paper we consider the eigenvalues and the Seidel eigenvalues of a chain graph. An$\dbar$elić, da Fonseca, Simić, and Du \cite{andelic2020tridiagonal} conjectured that there…

math.CO2023

The nullity of the net Laplacian matrix of a signed graph

Zhuang Xiong

Let $Γ = (G, σ)$ be a signed graph, where $G = (V (G), E (G))$ is an (unsigned) graph, called the underlying graph. The net Laplacian matrix of $Γ$ is defined as $L^{\pm}(Γ) = D^{\pm}(…

Extremal results for Kr+1−​-free signed graphs

Maxima of the index: forbidden unbalanced cycles

On the eigenvalues and Seidel eigenvalues of chain graphs

The nullity of the net Laplacian matrix of a signed graph

Extremal results for $K_{r + 1}^{-}$ -free signed graphs