On the spectral radius of the generalized adjacency matrix of a digraph

• Autor(a) principal: Baghipur, Maryam
• Data de Publicação: 2022
• Outros Autores: Ganie, Hilal A., Ghorbani, Modjtaba, Andrade, Enide
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/35242
• topic: Strongly connected digraph; Adjacency matrix; Aα-spectral radius; Maximum out-degree

Let $ D$ be a strongly connected digraph and $\alpha\in [0,1].$ In [J. P. Liu, X. Z. Wu, J. S. Chen and B. L. Liu, The $ A_{\alpha} $ spectral radius characterization of some digraphs, Linear Algebra Appl. 563 (2019) 63--74] the matrix $ A_{\alpha}(D)=\alpha Deg(D)+(1-\alpha)A(D),$ where $ A(D)$ and $Deg(D)$ are the adjacency matrix and the diagonal matrix of the out-degrees of $D,$ respectively, was defined. In this paper it is established some sharp bounds on the $A_{\alpha}(D)$-spectral radius in terms of some parameters such as the out-degrees, the maximum out-degree, the second maximum out-degree, the number of vertices, the number of arcs, the average $2$-outdegrees of the vertices of $D$ and the parameter $ \alpha$ of $A_{\alpha}(D)$. The extremal digraphs attaining these bounds are characterized. It is shown that the bounds obtained improve, in some cases, some of recently given bounds presented in the literature.