Demicompact linear operator. Essential pseudospectra and perturbation-Reference-Cited by-同舟云学术

Demicompact linear operator. Essential pseudospectra and perturbation

Published:2024-06-26 Issue: Volume: Page:
ISSN:1072-947X
Container-title:Georgian Mathematical Journal
language:en
Short-container-title:

Author:

Ammar Aymen¹,Daoud Houcem¹,Jeribi Aref²

Affiliation:

1. Department of Mathematics , Faculty of Sciences of Sfax , University of Sfax , Sfax , Tunisia

2. Department of Mathematics , Faculty of Sciences of Sfax , University of Sfax , Sfax , Tunisia ; Department of Mathematics and Statistics, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU) Riyadh, Saudi Arabia

Abstract

Abstract In this paper, we give new results on demicompact linear operators, study some properties and some results on Fredholm and upper semi-Fredholm relations involving demicompact operators. Our results are used to provide a fine description of the essential pseudospectra.

Publisher

Walter de Gruyter GmbH

Link

https://www.degruyter.com/document/doi/10.1515/gmj-2024-2032/pdf

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