ΙΔΙΟΤΗΤΕΣ ΚΑΙ ΕΦΑΡΜΟΓΕΣ ΤΩΝ ΜΕΤΑΘΕΣΕΩΝ ΤΟΥ ΣΥΝΟΛΟΥ [N]

We investigate the structured normwise and componentwise condition numbers for solving linear systems with Sylvester structure. Numerical examples show that the Sylvester structured condition numbers can be much smaller than the unstructured condition numbers. Here and hereafter, we denote ‖ · ‖ the spectral norm ‖ · ‖2 and ‖ · ‖∞ the infinity norm of its arguments. If A is a matrix, we write |A| = (|Aij |), where Aij is the (i, j)th entry of A. Let M n (R) denote the set of n× n real matrices with Sylvester structure.