The main eigenvalues of the Seidel matrix
Houqing Zhou · Mathematica Moravica · 2008
Let G be a simple graph with vertex set V (G) and (0, 1)-adjacency matrix A. As usual, A*(G) = J - I - 2A denotes the Seidel matrix of the graph G. The eigenvalue λ of A is said to be a main eigenvalue of G if the eigenspace ε(λ) is not orthogonal to the all-1 vector e. In this paper, relations between the main eigenvalues and associated eigenvectors of adjacency matrix and Seidel matrix of a graph are investigated. .