Let G be an n-vertex graph. If λ 1 , λ 2 , . . . , λ n and µ 1 , µ 2 , . . . , µ n are the ordinary (adjacency) eigenvalues and the Laplacian eigenvalues of G, respectively, then the Estrada index and the Laplacian Estrada index of G are defined as EE(G) = n i=1 e λ i and LEE(G) = n i=1 e µ i , resp
Estimating the Estrada index
✍ Scribed by José Antonio de la Peña; Ivan Gutman; Juan Rada
- Publisher
- Elsevier Science
- Year
- 2007
- Tongue
- English
- Weight
- 129 KB
- Volume
- 427
- Category
- Article
- ISSN
- 0024-3795
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📜 SIMILAR VOLUMES
Let G be a simple graph of order n with m edges. Let the adjacency spectrum be {λ 1 , λ 2 , . . . In [J.A. Peña, I. Gutman, J. Rada, Estimating the Estrada index, Linear Algebra Appl. 427 (2007) 70-76], Peña et al. posed a conjecture that the star S n has maximum Estrada index for any tree of order
4, 6)-fullerene a b s t r a c t Suppose G is a graph and λ 1 , λ 2 , . . . λ n are the eigenvalues of G. The Estrada index EE(G) of G is defined as the sum of the terms e λ i , 1 ≤ i ≤ n. In this work some upper and lower bounds for the Estrada index of (4, 6)-fullerene graphs are presented.
Lower and upper bounds on Szeged index of connected (molecular) graphs are established as well as Nordhaus-Gaddum-type results, relating the Szeged index of a graph and of its complement.