The Estrada Index
Zbornik radova, Tome 13 (2009) no. 21, p. 123
Cet article a éte moissonné depuis la source eLibrary of Mathematical Institute of the Serbian Academy of Sciences and Arts
If $\lambda_i,\;\;i=1,2,\ldots,n$, are the eigenvalues of the graph $G$,
then the Estrada index $EE$ of $G$ is the sum of the terms $e^{\lambda_i}$. This
graph invariant appeared for the first time in year 2000, in a paper
by Ernesto Estrada, dealing with the folding of protein molecules.
Since then a remarkable variety of other chemical and non-chemical
applications of $EE$ were communicated.
The mathematical studies of the Estrada index started only a few
years ago. Until now a number of lower and upper bounds were
obtained, and the problem of extremal $EE$ for trees solved. Also,
approximations and correlations for $EE$ were put forward, valid for
chemically interesting molecular graphs.
In this paper the relevant results on the Estrada index are surveyed.
Classification :
05C50 05C90 92E10
Keywords: Estrada index, spectrum (of graph), chemistry
Keywords: Estrada index, spectrum (of graph), chemistry
@article{ZR_2009_13_21_a5,
author = {Hanyuan Deng and Slavko Radenkovi\'c and Ivan Gutman},
title = {The {Estrada} {Index}},
journal = {Zbornik radova},
pages = {123 },
year = {2009},
volume = {13},
number = {21},
language = {en},
url = {http://geodesic.mathdoc.fr/item/ZR_2009_13_21_a5/}
}
Hanyuan Deng; Slavko Radenković; Ivan Gutman. The Estrada Index. Zbornik radova, Tome 13 (2009) no. 21, p. 123 . http://geodesic.mathdoc.fr/item/ZR_2009_13_21_a5/