Invariance of the strict Hurwitz property for polynomials with perturbed coefficients

Abstract

Given a strictly Hurwitz polynomial f(λ) = λn+ an-1λn-1+an-2λn-2+...+a1λ+a0, it is of interest to know how much the coefficients ai can be perturbed while simultaneously preserving the strict Hurwitz property. For systems with n ≤ 4, maximal intervals of the ai are given in a recent paper by Guiver and Bose [1]. In this note, a theorem of Kharitonov is exploited to obtain a general result for polynomials of any degree.