Results 51 to 60 of about 1,449 (134)
Preservers of pseudo spectra of operator Jordan triple products
, 2016 Let H be an infinite-dimensional complex Hilbert space and let L (H ) be the algebra of all bounded linear operators on H . For ε > 0 and T ∈ L (H ) , let rε (T ) denote the ε -pseudo spectral radius of T .
M. Bendaoud, A. Benyouness, M. Sarih
semanticscholar +1 more source
The Property (EA) and Local Spectral Theory
International Journal of Mathematics and Mathematical Sciences, Volume 2025, Issue 1, 2025.In this paper, we introduce and study the spectral property (EA). This property means that the difference between the approximate point spectrum and the upper semi‐Fredholm spectrum coincides with the difference between the approximate point spectrum and the upper semi‐Weyl spectrum.
Elvis Aponte +3 more
wiley +1 more source
Spectral integration and spectral theory for non‐Archimedean Banach spaces
International Journal of Mathematics and Mathematical Sciences, Volume 31, Issue 7, Page 421-442, 2002., 2002 Banach algebras over arbitrary complete non‐Archimedean fields are considered such that operators may be nonanalytic. There are different types of Banach spaces over non‐Archimedean fields. We have determined the spectrum of some closed commutative subalgebras of the Banach algebra ℒ(E) of the continuous linear operators on a free Banach space E ...
S. Ludkovsky, B. Diarra
wiley +1 more source
On unbounded commuting Jacobi operators and some related issues
Concrete Operators, 2019 We consider the situations, when two unbounded operators generated by infinite Jacobi matrices, are self-adjoint and commute. It is found that if two Jacobi matrices formally commute, then two corresponding operators are either self-adjoint and commute ...
Osipov Andrey
doaj +1 more source
International Journal of Mathematics and Mathematical Sciences, Volume 2025, Issue 1, 2025.For the Weinstein Laplacian considered on the Hilbert space which makes it a self‐adjoint operator, the Von Neumann spectral decomposition is given. As applications, a new integral representation for the Weinstein heat kernel is given. Also, it is proved that the spectrum of the semigroup associated with the Weinstein Laplacian is reduced to its ...
Abdelilah El Mourni +3 more
wiley +1 more source
Continuity and general perturbation of the Drazin inverse for closed linear operators
Abstract and Applied Analysis, Volume 7, Issue 6, Page 335-347, 2002., 2002 We study perturbations and continuity of the Drazin inverse of a closed linear operator A and obtain explicit error estimates in terms of the gap between closed operators and the gap between ranges and nullspaces of operators. The results are used to derive a theorem on the continuity of the Drazin inverse for closed operators and to describe the ...
N. Castro González +2 more
wiley +1 more source
On a class of $h$-Fourier integral operators
, 2013 In this paper, we study the $L^{2}$-boundedness and $L^{2}$-compactness of a class of $h$-Fourier integral operators. These operators are bounded (respectively compact) if the weight of the amplitude is bounded (respectively tends to $0)$
Abderrahmane, Senoussaoui +1 more
core +2 more sources
Nonlocal heat equations with generalized fractional Laplacian
Advances in Nonlinear AnalysisWe study heat equations with generalized fractional Laplacian, which is defined by the spectral theory. Here we develop the existence theory for those equations. Also, we present some numerical simulations for our problems.
Kossowski Igor, Przeradzki Bogdan
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Negative Powers of Contractions Having a Strong AA+ Spectrum
Moroccan Journal of Pure and Applied Analysis, 2023 Zarrabi proved in 1993 that if the spectrum of a contraction T on a Banach space is a countable subset of the unit circle 𝕋, and if limn→+∞log(‖T−n‖)n=0{\lim _{n \to + \infty }}{{\log \left( {\left\| {{T^{ - n}}} \right\|} \right)} \over {\sqrt n ...
Esterle Jean
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Schrödinger operators with potential waveguides on periodic graphs
, 2020 We consider discrete Schrödinger operators with periodic potentials on periodic graphs perturbed by guided positive potentials, which are periodic in some directions and finitely supported in other ones.
O. Post, N. Saburova
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