Abstract
Let G be a simple graph with n vertices and (Formula presented.) -adjacency matrix A. As usual, (Formula presented.) denotes the Seidel matrix of the graph G. Suppose (Formula presented.) and (Formula presented.) are the eigenvalues of the adjacency matrix and the Seidel matrix of G, respectively. The Estrada index of the graph G is defined as (Formula presented.). We define and investigate the Seidel-Estrada index, (Formula presented.). In this paper the basic properties of the Seidel-Estrada index are investigated. Moreover, some lower and upper bounds for the Seidel-Estrada index in terms of the number of vertices are obtained. In addition, some relations between (Formula presented.) and the Seidel energy (Formula presented.) are presented.
| Original language | English |
|---|---|
| Article number | 120 |
| Journal | Journal of Inequalities and Applications |
| Volume | 2016 |
| Issue number | 1 |
| DOIs | |
| State | Published - 1 Dec 2016 |
Keywords
- eigenvalue
- Seidel matrix
- Seidel-Estrada index