Results 31 to 40 of about 20,701 (195)

The Generalized Fredholm Operators [PDF]

Transactions of the American Mathematical Society, 1976
Let X, Y be Banach spaces over either the real field or the complex field. A continuous linear operator will be called a generalized Fredholm operator if T ( X ) T(X) is closed in Y, and Ker T and Coker T are reflexive Banach spaces.
openaire   +2 more sources

Left and Right B-Fredholm Operators

Ukrainian Mathematical Journal, 2022
UDC 517.9 We introduce the families of left and right B-Fredholm operators in Banach space, realize their stabilization with the help of finite-rank operators, and  prove a spectral mapping theorem for the left and right B-Fredholm operators.
Abdmouleh, F., Lakhal, T. Ben
openaire   +2 more sources

An invertibility criterion in a C*-algebra acting on the Hardy space with applications to composition operators

, 2017
In this paper we prove an invertibility criterion for certain operators which is given as a linear algebraic combination of Toeplitz operators and Fourier multipliers acting on the Hardy space of the unit disc.
Gül, Uğur, Koca, Beyaz Başak
core   +1 more source

Perturbation Results on Semi-Fredholm Operators and Applications

Journal of Inequalities and Applications, 2009
We give some results concerning stability in the Fredholm operators and Browder operators set, via the concept of measure of noncompactness. Moreover, we prove some localization results on the essential spectra of bounded operators on Banach space.
Boulbeba Abdelmoumen, Hamadi Baklouti
doaj   +2 more sources

Unbounded generalized B-Fredholm operators

Extracta Mathematicae
In this paper, we investigate a new class of unbounded linear operators, that is, the unbounded generalized B-Fredholm operators in Banach space. More explicitly, we provide a characterization of this class of operators and some of its basic properties ...
M. Boudhief
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Fredholm conditions on non-compact manifolds: theory and examples

, 2017
We give explicit Fredholm conditions for classes of pseudodifferential operators on suitable singular and non-compact spaces. In particular, we include a "user's guide" to Fredholm conditions on particular classes of manifolds including asymptotically ...
Carvalho, Catarina, Nistor, Victor, Qiao, Yu   +2 more
core   +1 more source

Tauberian operators in p-adic analysis

International Journal of Mathematics and Mathematical Sciences, 2000
In archimedean analysis Tauberian operators and operators having property N were defined by Kalton and Wilansky (1976). We give several characterizations of p-adic Tauberian operators and operators having property N in terms of basic sequences.
Takemitsu Kiyosawa
doaj   +1 more source

Multiplication Operators on Cesàro Sequence Spaces

Demonstratio Mathematica, 2016
In this paper we characterize the compact, invertible and Fredholm multiplication operators on Cesàro sequence spaces.
Komal B. S., Pandoh Suruchi, Raj Kuldip
doaj   +1 more source

Linear Toroidal‐Inertial Waves on A Differentially Rotating Sphere with Application to Helioseismology: Modeling, Forward and Inverse Problems

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT This paper develops a mathematical framework for interpreting observations of solar inertial waves in an idealized setting. Under the assumption of purely toroidal linear waves on the sphere, the stream function of the flow satisfies a fourth‐order scalar equation.
Tram Thi Ngoc Nguyen, Damien Fournier, Laurent Gizon, Thorsten Hohage   +3 more
wiley   +1 more source

Essential spectra in non-Archimedean fields

Математичні Студії, 2022
In the paper we extend some aspects of the essential spectra theory of linear operators acting in non-Archimedean (or p-adic) Banach spaces. In particular, we establish sufficient conditions for the relations between the essential spectra of the sum of ...
A. Ammar, F. Z. Boutaf, A. Jeribi
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