Perturbation bounds for polynomials

  • Authors:
  • A. Galántai;C. J. Hegedűs

  • Affiliations:
  • University of Miskolc, 3515, Miskolc, Hungary and Budapest Tech, John von Neumann Faculty of Informatics, Bécsi út 96/b, 1034, Budapest, Hungary;Eötvös Loránd University, Pázmány Péter sétány 1/c, 1117, Budapest, Hungary

  • Venue:
  • Numerische Mathematik
  • Year:
  • 2008

Quantified Score

Hi-index 0.00

Visualization

Abstract

Using two different elementary approaches we derive a global and a local perturbation theorem on polynomial zeros that significantly improve the results of Ostrowski (Acta Math 72:99–257, 1940), Elsner et al. (Linear Algebra Appl 142:195–209, 1990). A comparison of different perturbation bounds shows that our results are better in many cases than the similar local result of Beauzamy (Can Math Bull 42(1):3–12, 1999). Using the matrix theoretical approach we also improve the backward stability result of Edelman and Murakami (Proceedings of the Fifth SIAM Conference on Applied Linear Algebra, SIAM, Philapdelphia, 1994; Math Comput 64:210–763, 1995).