Bounds For The Distance Estrada Index Of Graphs
arXiv:1205.1189
Abstract
The D-eigenvalues μ_1,μ_2,...,μ_{n} of a connected graph G are the eigenvalues of its distance matrix. The distance Estrada index of G is defined in [15] as DEE=DEE(G)=Σ_{i=1}^n e^{μ_{i}} In this paper, we give better lower bounds for the distance Estrada index of any connected graph as well as some relations between DEE(G) and the distance energy.