Let G be a graph whose eigenvalues are λ1, λ2,...,λn. The Estrada index of G is equal to ∑i = 1n eλi. We point out certain classes of graphs whose characteristic polynomials are closely connected to the Chebyshev polynomials of the second kind. Various relations, in particular approximations, for the Estrada index of these graphs are obtained.
|Number of pages||3|
|Journal||Chemical Physics Letters|
|State||Published - 20 Mar 2008|
ASJC Scopus subject areas
- Physics and Astronomy (all)
- Physical and Theoretical Chemistry