Discrete Optimization ( IF 1.1 ) Pub Date : 2022-12-24 , DOI: 10.1016/j.disopt.2022.100758 Qixuan Yuan , Ruifang Liu , Jinjiang Yuan
For , let be the -matrix of , where is the diagonal degree matrix of and is the adjacency matrix of Let denote the -spectral radius of a graph . Let be a -connected nonregular graph with vertices, edges, maximum degree and minimum degree . In this paper, we show that which extends the result on the spectral radius of Xue and Liu (0000) and improves the result on the signless Laplacian spectral radius of Shiu et al. (2017). Furthermore, we also prove that which extends the result on the signless Laplacian spectral radius of Ning et al. (2018).
Let be a -strong nonregular digraph of order , size , and maximum outdegree . For , let be the -matrix of where is the diagonal matrix of its vertex outdegrees and is the adjacency matrix of Denote by the -spectral radius of a digraph . We prove that which improves the result of Xi and Wang (2020). In the end of the paper, related problem is mentioned.
中文翻译:
非常规图(digraph)的Aα-谱半径和最大度(outdegree)
为了, 让成为-矩阵, 在哪里是的对角线度矩阵和是邻接矩阵让表示-图的谱半径. 让是一个-连接的非常规图顶点,边缘,最大程度和最低学历. 在本文中,我们表明它扩展了 Xue 和 Liu (0000) 谱半径的结果,改进了 Shiu 等人的无符号拉普拉斯谱半径的结果。(2017)。此外,我们还证明这扩展了 Ning 等人的无符号拉普拉斯谱半径的结果。(2018)。
让是一个-强非常规有序有向图, 尺寸, 和最大出度. 为了, 让成为-矩阵在哪里是顶点出度的对角矩阵,是邻接矩阵表示为这-有向图的谱半径. 我们证明这改进了 Xi 和 Wang (2020) 的结果。在论文的最后,提到了相关问题。