Czechoslovak Mathematical Journal, first online, pp. 1-12
Main eigenvalues of real symmetric matrices with application to signed graphs
Received March 29, 2019. Published online April 14, 2020.
Abstract: An eigenvalue of a real symmetric matrix is called main if there is an associated eigenvector not orthogonal to the all-1 vector $ j$. Main eigenvalues are frequently considered in the framework of simple undirected graphs. In this study we generalize some results and then apply them to signed graphs.
Keywords: main angle; signed graph; adjacency matrix; Laplacian matrix; Gram matrix