令A(G)表示G的邻接矩阵,Q(G)=D(G)+A(G)是G的无符号拉普拉斯矩阵,Q(G)的最大特征值是G的无符号拉普拉斯谱半径.在这篇文章中,我们分别确定了给定点连通度、给定块数和给定悬挂点数的图类中无符号拉普拉斯谱半径最大的图的结构.
Let A(G) be the adjacent matrix of G and Q(G) = D(G) + A(G) is the signless Laplacian matrix of G.The signless Laplacian spectral radius of G is the largest eigenvalue of Q(G).In this paper we characterize the graphs with the maximum signless Laplacian spectral radii among the graphs with given vertex connectivity,among the graphs with given number of blocks and among the graphs with given pendant vertices,respectively.