Estimating the Estrada index
Estimating the Estrada index
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DOI:
10.1016/j.laa.2007.06.020
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发表时间:
2007-11-01
影响因子:
1.1
通讯作者:
Rada, Juan
中科院分区:
文献类型:
--
作者:
de la Pena, Jose Antonio;Gutman, Ivan;Rada, Juan
Let G be a graph on n vertices, and let lambda(1), lambda(2), . . . , lambda(n) be its eigenvalues. The Estrada index of G is a recently introduced graph invariant, defined as EE = Sigma(n)(i) =, e(lambda i). We establish lower and upper bounds for EE in terms of the number of vertices and number of edges. Also some inequalities between EE and the energy of G are obtained. (c) 2007 Elsevier Inc. All rights reserved.