Results 11 to 20 of about 42 (41)
Ascent, descent and additive preserving problems [PDF]
, 2019 Given an integer n ≥ 1, we provide a complete description of all additive surjective maps, on the algebra of all bounded linear operators acting on a complex separable infinite-dimensional Hilbert space, preserving in both directions the set of all ...
OUDGHIRI, Mourad, SOUILAH, Khalid
core +2 more sources
Spectral Analysis of the Incompressible Viscous Rayleigh–Taylor System in R3
, 2022 International audienceThe linear instability study of the viscous Rayleigh-Taylor model in the neighborhood of a laminar smooth increasing density profile ρ 0 (x 3) amounts to the study of the following ordinary differential equation of order 4 − λ 2 [ρ ...
Lafitte, Olivier, Nguyễn, Tiến-Tài
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Fixed Point in Non-Archimedeant T -Banach Spaces [PDF]
In this paper, we introduce the concept of T -normed space in a non-Archimedean space, which is called a non-Archimedean T -normed space and give some properties.
TALLAB , ABDELHAMID +2 more
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The basic propositions on defect numbers, root numbers and indices of linear operators [PDF]
, 2020 : In this work, we use the notion of the measure of noncompactness in order to establish some results concerning the class of semi-Fredholm and Fredholm operators.
Weidmann +13 more
core
Operators with equal projections related to their generalized inverses [PDF]
, 2004 In this article we characterize operators on Banach spaces which have the same projections related to their outer or inner generalized inverses. As corollaries, we obatin well-known results for the Drazin inverse of bounded operators. Keywords: Outer and
Yimin Wei, Dragan S Djordjević
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Spectral points of type π+ and type π- of closed operators in indefinite inner product spaces [PDF]
, 2014 We introduce the notion of spectral points of type π+ and type π− of closed operators A in a Hilbert space which is equipped with an indefinite inner product. It is shown that these points are stable under compact perturbations.
Trunk, Carsten, Philipp, Friedrich
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Computation of Eigenvalues of Discrete Lower Semibounded Operators
, 2016 Based on the Galerkin method, the formulas for eigenvalues of discrete lower semibounded operators were obtained. Numerical experiments demonstrated high accuracy and computational efficiency of them.
Galiya A Zakirova, Sergey I Kadchenko
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Perturbation Bounds For Isotropic Invariant Subspaces Of Skew-Hamiltonian Matrices
, 2008 We investigate the behavior of isotropic invariant subspaces of skew-Hamiltonian matrices under structured perturbations. It is shown that finding a nearby subspace is equivalent to solving a certain quadratic matrix equation.
Daniel Kressner
core
, 2001 Let (U(t))t≥0 be a C0-semigroup of bounded linear operators on a Banach space X. In this paper, we establish that if, for some t0> 0, U(t0) is a Fredholm (resp., semi-Fredholm) operator, then (U(t))t≥0 is a Fredholm (resp., semi-Fredholm) semi-group ...
Khalid Latrach, Abdelkader Dehici
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On the Properties for Iteration of a Compact Operator with Unstructured Perturbation
, 1996 . We consider certain speed estimates for Krylov subspace methods (such as GMRES) when applied upon systems consisting of a compact operator K with small unstructured perturbation B.
Jarmo Malinen
core