A decreasing sequence of eigenvalue localization regions
A decreasing sequence of rectangles \((R_ p)\), \(p \geq 0\), is constructed in such a way that all the eigenvalues of a complex matrix \(A\) of order \(n + 1\), \(n \in \mathbb{N}\), are contained in each rectangle \(R_ p\). When \(A\) is a matrix with real spectrum or a normal matrix, each rectangle \(R_ p\) can be computed without knowing the eigenvalues of the matrix \(A\).
scientific article; zbMATH DE number 519702