具有最大无符号拉普拉斯谱半径的拟树

On the maximum signless Laplacian spectral radius of quasi-tree Graph

若存在一个顶点,使得删除这个点后得到的图是一个树,则称该图是拟树,该文基于拟树的概念,利用相应的枝节变换,刻画了固定某个顶点的度及给定悬挂点数的所有拟树中具有最大无符号拉普拉斯谱半径的极图.

A graph is a quasi-tree graph,if there is a vertex,such that delete this vertex is a tree.Based on the concept of quasi-tree,and by the corresponding branch transformation.In this paper,the graphs with maximum signless Laplacian spectral radius among all quasi-tree graph with fixed some vertex degree and given pendent vertices are characterized.