A perturbation characterization of compactness of self-adjoint operators

• Autorzy: Heydar Radjavi , Ping-Kwan Tam , Kok-Keong Tan
• Języki publikacji: EN

Abstrakty

EN

A characterization of compactness of a given self-adjoint bounded operator A on a separable infinite-dimensional Hilbert space is established in terms of the spectrum of perturbations. An example is presented to show that without separability, the perturbation condition, which is always necessary, is not sufficient. For non-separable spaces, another condition on the self-adjoint operator A, which is necessary and sufficient for the perturbation, is given.

Kategorie tematyczne

• 47A55: Perturbation theory
• 47B07: Operators defined by compactness properties

• Wydawca: Institute of Mathematics Polish Academy of Sciences
• Czasopismo: Studia Mathematica
• Rocznik: 2003
• Tom: 158
• Numer: 3
• Strony: 199-205

Daty

wydano

2003

Twórcy

autor

Heydar Radjavi

• Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 3J5

autor

Ping-Kwan Tam

• Department of Mathematics, Chinese University of Hong Kong, Shatin, New Territories, Hong Kong

autor

Kok-Keong Tan

• Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 3J5

Identyfikatory

DOI

10.4064/sm158-3-1