Zobrazeno 1 - 10
of 43
pro vyhledávání: '"Zariouh, Hassan"'
We prove that a bounded linear operator $T$ is a direct sum of an invertible operator and an operator with at most countable spectrum iff $0\notin\mbox{acc}^{\omega_{1}}\,\sigma(T),$ where $\omega_{1}$ is the smallest uncountable ordinal and $\mbox{a
Externí odkaz:
http://arxiv.org/abs/2211.07736
This paper treatises the preservation of some spectra under perturbations not necessarily commutative and generalizes several results which have been proved in the case of commuting operators.
Comment: 13
Comment: 13
Externí odkaz:
http://arxiv.org/abs/2209.01086
We study the stability of certain spectra under some algebraic conditions weaker than the commutativity and we generalize many known commutative perturbation results.
Externí odkaz:
http://arxiv.org/abs/2207.08577
The Kato's decomposition \cite[Theorem 4]{kato} is generalized to semi-B-Fredholm operators.
Externí odkaz:
http://arxiv.org/abs/2112.10262
The index of a pseudo B-Fredholm operator will be defined and generalize the usual index of a B-Fredholm operator. This concept will be used to extend some known results in Fredholm's theory. Among other results, the nullity, the deficiency, the asce
Externí odkaz:
http://arxiv.org/abs/2112.02407
The main purpose of this paper, is to introduce and study the classes $(ab_{e})$ and $(aw_{e})$ which are strongly related to what has been recently studied in \cite{aznay-zariouh}. Furthermore, we give the connection between these classes and those
Externí odkaz:
http://arxiv.org/abs/2109.13350
Autor:
Aznay, Zakariae, Zariouh, Hassan
It is well known that an hyponormal operator satisfies Weyl's theorem. A result due to Conway shows that the essential spectrum of a normal operator $N$ consists precisely of all points in its spectrum except the isolated eigenvalues of finite multip
Externí odkaz:
http://arxiv.org/abs/2105.02131
Autor:
Ouidren, kaoutar Ben, Zariouh, Hassan
The purpose of this paper is to introduce and study new extension of Rako\v{c}evi\'{c}'s property $(w)$ and property $(b)$ introduced by Berkani--Zariouh in \cite{berkani-zariouh1}, in connection with other Weyl type theorems and recent properties. W
Externí odkaz:
http://arxiv.org/abs/2007.11710
Autor:
Aznay, Zakariae, Zariouh, Hassan
In this paper, we continue the study of property $(UW_{\Pi})$ introduced in \cite{berkani2}, in connection with other Weyl type theorems. Moreover, we give counterexamples to show that some recent results related to this property, which are announced
Externí odkaz:
http://arxiv.org/abs/2007.02451
Publikováno v:
In Linear Algebra and Its Applications 1 September 2023 672:108-121
