具有n-4个悬挂点的双圈补图的最小特征值的下界

The Lower Bounds of the Least Eigenvalue of Complements of Bicyclic Graphs with n−4 Pendant Vertices

图的最小特征值作为刻画图结构性质的参数具有重要的研究意义,且相比于谱半径,图的最小特征值研究较少.在补图简单无向且连通的情况下,通过运用相关知识分析,在有n-4个悬挂点的n阶双圈图集中刻画了最小邻接特征值的下界.

The least eigenvalue as a parameter to characterize the structural properties of a graph,has important research value.Comparing with the spectral radius,the least eigenvalue of a graph is less studied.The graphs in this paper are simple,undirected and connected,and we characterize the lower bounds of the least adjacency eigenvalue of graphs in the set of bicyclic graphs with n vertices and n−4 pendant vertices by using relevant knowledge analysis and demonstration.