Spectraloid operator polynomials, the approximate numerical range and an Eneström-Kakeya theorem in Hilbert space

• Autorzy: Jan Swoboda , Harald K. Wimmer
• Języki publikacji: EN

Abstrakty

EN

We study a class of operator polynomials in Hilbert space which are spectraloid in the sense that spectral radius and numerical radius coincide. The focus is on the spectrum in the boundary of the numerical range. As an application, the Eneström-Kakeya-Hurwitz theorem on zeros of real polynomials is generalized to Hilbert space.

Kategorie tematyczne

• 47A56: Functions whose values are linear operators (operator and matrix valued functions, etc., including analytic and meromorphic ones)
• 47A12: Numerical range, numerical radius
• 47A10: Spectrum, resolvent

• Wydawca: Institute of Mathematics Polish Academy of Sciences
• Czasopismo: Studia Mathematica
• Rocznik: 2010
• Tom: 198
• Numer: 3
• Strony: 279-300

Daty

wydano

2010

Twórcy

autor

Jan Swoboda

• Max-Planck-Institut für Mathematik, D-53111 Bonn, Germany

autor

Harald K. Wimmer

• Mathematisches Institut, Universität Würzburg, D-97074 Würzburg, Germany

Identyfikatory

DOI

10.4064/sm198-3-7