广义Bethe树是指每层上的点都具有相同度的带根树.设既为具有k层的广义Bethe树,К^τ为τ阶完全图.把τ个В_κ的根点分别粘在К^τ的τ个点上,可获得一个图В_κοК^τ .借助于К阶对称三对角矩阵,本文给出邻接矩阵A(В_κοК^τ )和Laplace矩阵L(В_κοК^τ )的特征值的简洁刻画.此外,本文还给出了A(В_κοК^τ )的Perron向量的结构性质.
A generalized Bethe tree is a rooted tree for which the vertices in each level having equal degree. Let Вk be a generalized Bethe tree of k level, and let К^τ be a complete graph on r vertices. Then a graph В_κοК^τ is obtained from r copies ofВk and К^τ by appending r roots to the vertices of К^τ, respectively. In this paper, a simple way is introduced to characterize the eigenvalues of the adjacency matrix A(В_κοК^τ)and the Laplaeian matrix L(В_κοК^τ)of В_κοК^τ means of symmetric tridiagonal matrices of order k. In addition, the structure property of the Perron vectors of A(В_κοК^τ)is given.