Results 221 to 230 of about 166,406,602 (248)

Perturbation theory for nullity, deficiency and other quantities of linear operators

Journal D'Analyse Mathematique, 1958
Tosio Kato
exaly   +2 more sources

A Short Introduction to Perturbation Theory for Linear Operators

1982
exaly   +2 more sources

Perturbation theory for a linear operator

Mathematical Proceedings of the Cambridge Philosophical Society, 1967
AbstractWe extend certain results of the theory of closed operators in Banach spaces to general linear operators in normed spaces. A ‘state diagram’ for linear operators is drawn up. We prove some perturbation theorems, improving or correcting certain results of Goldberg.
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Perturbation theory of lower semi-Browder multivalued linear operators

Publicationes Mathematicae Debrecen, 2011
In the present paper we introduce the notion of lower semi-Browder linear relation and we study the perturbation problem under compact operator perturbations.
FATMA FAKHFAKH, MAHER MNIF
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Spectral Theory for Perturbations of Unbounded Linear Operators

2016
In this chapter we first study the spectral theory of completely continuous perturbations of unbounded Fredholm operators in the non-archimedean Hilbert space \( \mathbb{E}_{\omega } \).
Toka Diagana, François Ramaroson
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Connection between perturbation theory, projection-operator techniques, and statistical linearization for nonlinear systems

Physical Review A, 1978
We employ the equivalence between Zwanzig's projection-operator formalism and perturbation theory to demonstrate that the approximate-solution technique of statistical linearization for nonlinear stochastic differential equations corresponds to the lowest-order ..beta..
Aaron B. Budgor, Bruce J. West
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Spectral Theory for Perturbations of Bounded Diagonal Linear Operators

2016
Our main goal in this chapter consists of computing the spectrum of the class of bounded linear operators, \( A = D + F \) where D is a diagonal operator and F is a finite rank operator. In order to achieve that, we will make extensive use of the theory of Fredholm operators and the notion of essential spectrum.
Toka Diagana, François Ramaroson
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Perturbation of the spectrum and wave operators in linear transport theory

Russian Mathematical Surveys, 1999
Summary: We study spectral properties of a nonself-adjoint integro-differential operator \[ L=L_0+iV=i\mu\;\frac{\partial}{\partial x}+ic(x)\int^1_{-1}\cdot\;d\mu \] acting on the space \({\mathcal H}= L^2(\mathbb{R}\times [-1,1])\), with domain \(\{\psi\in{\mathcal H}:\psi(\cdot,\mu)\) absolutely continuous for almost all \(\mu\in[-1,1]\), \(L_0\psi ...
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Low-order scaling local correlation methods II: Splitting the Coulomb operator in linear scaling local second-order Møller–Plesset perturbation theory

The Journal of Chemical Physics, 2000
A novel multipole approximation for the linear scaling local second-order Møller–Plesset perturbation theory (MP2) method is presented, which is based on a splitting of the Coulomb operator into two terms. The first one contains the singularity and is rapidly decaying with increasing distance. It is treated by a conventional two-electron transformation,
Georg Hetzer, Martin Schütz, Hermann Stoll, Hans-Joachim Werner   +3 more
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Methods of abstract harmonic analysis in the perturbation of linear operators

Siberian Mathematical Journal, 1983
The basic results of the paper refer to questions of similarity of a certain class of non-self-adjoint operators. Methods of abstract harmonic analysis for operators from certain group algebras connected with an unperturbed operator are used. Applications are criteria for the spectrality of perturbed spectral operators with discrete spectrum ...
openaire   +3 more sources