Some Properties on Estrada Index of Folded Hypercubes Networks

Let G be a simple graph with n vertices and let λ1,λ2,…,λn be the eigenvalues of its adjacency matrix; the Estrada index EEG of the graph G is defined as the sum of the terms eλi,  i=1,2,…,n. The n-dimensional folded hypercube networks FQn are an important and attractive variant of the n-dimensional...

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Bibliographic Details
Main Authors: Jia-Bao Liu, Xiang-Feng Pan, Jinde Cao
Format: Article
Language:English
Published: Hindawi Limited 2014-01-01
Series:Abstract and Applied Analysis
Online Access:http://dx.doi.org/10.1155/2014/167623
Description
Summary:Let G be a simple graph with n vertices and let λ1,λ2,…,λn be the eigenvalues of its adjacency matrix; the Estrada index EEG of the graph G is defined as the sum of the terms eλi,  i=1,2,…,n. The n-dimensional folded hypercube networks FQn are an important and attractive variant of the n-dimensional hypercube networks Qn, which are obtained from Qn by adding an edge between any pair of vertices complementary edges. In this paper, we establish the explicit formulae for calculating the Estrada index of the folded hypercubes networks FQn by deducing the characteristic polynomial of the adjacency matrix in spectral graph theory. Moreover, some lower and upper bounds for the Estrada index of the folded hypercubes networks FQn are proposed.
ISSN:1085-3375
1687-0409