The Estrada Index
Zbornik radova, Tome 13 (2009) no. 21, p. 123
Voir la notice de l'article provenant de 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 },
publisher = {mathdoc},
volume = {13},
number = {21},
year = {2009},
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/