图的Laplacian谱半径的一个新上界  

A New Upper Bound for the Laplacian Spectral Radius of Graphs

作　　者：徐淮涓[1] 

机构地区：[1]淮阴师范学院数学系,江苏淮安223300

出　　处：《淮阴师范学院学报（自然科学版）》2007年第2期96-98,共3页Journal of Huaiyin Teachers College;Natural Science Edition

摘　　要：设G为n阶简单连通图.若Q(G)为图G的对角矩阵与邻接矩阵的和,称Q(G)为G的拟-Laplacian矩阵.讨论了Q(G)的性质并利用G的顶点数、边数、最大度和最小度给出了图G的Laplacian矩阵谱半径的一个新上界.Let G be a simple connected graph with n vertices. The matrix Q（ G）is said the quasi-Laplacian matrix of G, if it is the stun of the diagonal matrix and the adjacency matrix of G. In this paper, we study some properties of the quasi-Laplacian matrices of G, Moreover we obtain new upper bounds of spectral radius of Laplacian matrices of graphs in terms of the vertex number,the edge number,the largest degree,and the smallest degree of G.

关 键 词：图 LAPLACIAN矩阵 谱半径 上界 

分 类 号：O157.5[理学—数学]