Invariant Subspace Problem for Norm Attaining Operators

Authors

  • Aissa Nasli Bakir Department of mathematics, Faculty of exact science and informatics, Laboratory of Mathematics and its Applications LMA, Hassiba Benbouali University of Chlef, algeria
  • Ayyoub Fellag Ariouat Department of mathematics, Faculty of exact science and informatics, Laboratory of Mathematics and its Applications LMA, Hassiba Benbouali University of Chlef, algeria
  • Abdelkader Benali
  • Ibrahim Alraddadi Department of Mathematics, Faculty of Science, Islamic University of Madinah, Madinah, Saudi Arabia
  • Saad M. Almuaddi Basic Applied Scientific Research Center, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia Mathematics Department, College of Science, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia

DOI:

https://doi.org/10.29020/nybg.ejpam.v18i4.6739

Keywords:

Quasi-∗-paranormal operators, Invariant subspaces, Norm attaining operators, Absolutely norm attaining operator, fractional derivatives; differential equations; fractional differential equations; antiperiodic; nonlocal boundary conditions; existence.

Abstract

Our aim is to characterize norm attaining and absolutely norm attaining quasi-∗-paranormal operators and class Ωn operators defined on a separable Hilbert space. We define invariant non trivial subspaces for the con- sidered operators and we give a matrix representation under certain condition. Compacity, reduisant subspaces and the normality of such operators are also established.

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Published

2025-11-05

Issue

Vol. 18 No. 4: (October 2025)

Section

Mathematical Analysis

License

Copyright (c) 2025 Aissa Nasli Bakir, Ayyoub Fellag Ariouat , Abdelkader Benali, Ibrahim Alraddadi, Saad M. Almuaddi

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How to Cite

Invariant Subspace Problem for Norm Attaining Operators. (2025). European Journal of Pure and Applied Mathematics, 18(4), 6739. https://doi.org/10.29020/nybg.ejpam.v18i4.6739