Startseite Demicompactness perturbation in Banach algebras and some stability results
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Demicompactness perturbation in Banach algebras and some stability results

  • Slim Chelly , Aref Jeribi und Bilel Krichen ORCID logo EMAIL logo
Veröffentlicht/Copyright: 26. Oktober 2022
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Abstract

In this paper, we introduce and investigate a new concept that we call demicompact elements in Banach algebras as a generalization of demicompact linear operators acting on Banach spaces. Our concept is used to construct a new class of Fredholm perturbations with respect to a given Banach subalgebra B, that contains an inessential ideal k B and the set of left Fredholm perturbations introduced in [A. Ben Ali and N. Moalla, Fredholm perturbation theory and some essential spectra in Banach algebra with respect to subalgebra, Indag. Math. (N. S.) 28 2017, 2, 276–286]. We show that it is a two-sided closed ideal of B playing an important role in the characterization of the Weyl spectrum of elements affiliated with B.

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Received: 2021-12-10
Accepted: 2022-05-04
Published Online: 2022-10-26
Published in Print: 2023-02-01

© 2022 Walter de Gruyter GmbH, Berlin/Boston

Heruntergeladen am 6.9.2025 von https://www.degruyterbrill.com/document/doi/10.1515/gmj-2022-2192/pdf
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