图的距离Estrada指数

On the Distance Estrada Index of Graphs

设G是一个n阶连通图,G的距离特征值为γ1≥γ2≥…≥γn,定义图G的距离Estrada指数如下:DEE(G)=∑neγi.该文研究图的距离Estrada指数的性质,并给出了DEE的一些界.

Let G be a connected graph of order n,let γ1≥γ2≥…≥γn≥ be the eigenvalues of the distance matrix.The distance Estrada index,DEE（G）,of G is defined as DEE（G）=∑ni=1eγi.In this paper we obtain some properties of DEE,also we establish some bounds for DEE.