Summary
International Symposium on Nonlinear Theory and its Applications
2009
Session Number:A3L-A
Session:
Number:A3L-A2
Verified Error Bounds for Double Roots of Nonlinear Equations
Siegfried M. Rump, Shin’Ichi Oishi,
pp.-
Publication Date:2009/10/18
Online ISSN:2188-5079
Summary:
It is well known that it is an ill-posed problem to decide whether a function has a multiple root. For example, an arbitrarily small perturbation of a real polynomial may change a double real root into two distinct real or complex roots. In this paper we describe a computational method for the verified computation of a complex disc to contain exactly 2 roots of a univariate nonlinear function. The function may be given by some program. Computational results using INTLAB, the Matlab toolbox for reliable computing, demonstrate properties and limits of the method.