Results 61 to 70 of about 281,037 (176)

Operator logarithms and exponentials

, 2007
Since Mclntosh's introduction of the 𝛨∞-calculus for sectorial operators, the topic has been studied by many authors. Haase has constructed a similar functional calculus for strip-type operators, and has also developed an abstract framework which unifies both of these examples and more. In this thesis we use this abstract functional calculus setting to
Clark, S, Clark, Stephen
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Exponential splitting for unbounded operators [PDF]

Mathematics of Computation, 2009
Summary: We present a convergence analysis for exponential splitting methods applied to linear evolution equations. Our main result states that the classical order of the splitting method is retained in a setting of unbounded operators, without requiring any additional order condition.
Hansen, Eskil, Ostermann, Alexander
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The spaces of exponential type vectors of complex degrees of positive operators

Karpatsʹkì Matematičnì Publìkacìï, 2010
New classes of interpolation spaces of exponential type vectors of complex degrees of positive operators are defined. Properties of the approximation spaces generated by the considered interpolation spaces are investigated.
Dmytryshyn M.I.
doaj  

Approximation by bivariate Bernstein–Kantorovich–Stancu operators that reproduce exponential functions

Journal of Inequalities and Applications
In this study, we construct a Stancu-type generalization of bivariate Bernstein–Kantorovich operators that reproduce exponential functions. Then, we investigate some approximation results for these operators.
Lian-Ta Su, Kadir Kanat, Melek Sofyalioğlu Aksoy, Merve Kisakol   +3 more
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Generalized Hermite Polynomials and the Heat Equation for Dunkl Operators

, 1997
Based on the theory of Dunkl operators, this paper presents a general concept of multivariable Hermite polynomials and Hermite functions which are associated with finite reflection groups on $\b R^N$.
Rösler, Margit
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Exponential decay estimates for Singular Integral operators [PDF]

, 2013
The following subexponential estimate for commutators is proved |[|\{x\in Q: |[b,T]f(x)|>tM^2f(x)\}|\leq c\,e^{-\sqrt{\alpha\, t\|b\|_{BMO}}}\, |Q|, \qquad t>0.\] where $c$ and $\alpha$ are absolute constants, $T$ is a Calder\'on--Zygmund operator, $M ...
Ortiz-Caraballo, Carmen, Pérez, Carlos, Rela, Ezequiel   +2 more
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Estimating the operator exponential

Linear Algebra and its Applications, 1998
The paper deals with the strongly continuous semigroup \(V(t)\) such that the strong integral \(X=\int^{\infty}_{0}V(t)^{\ast}V(t)dt\) represents an everywhere defined and therefore bounded self-adjoint operator. Such a semigroup generalizes the exponential function \(V(t)=e^{At}\) with a square matrix \(A\).
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On Baskakov operators preserving the exponential function

Journal of Numerical Analysis and Approximation Theory, 2017
In this paper, we are concerned about the King-type Baskakov operators defined by means of the preserving functions \(e_{0}\) and \(e^{2ax},\ a>0\) fixed.
Ovgu Gurel Yilmaz, Vijay Gupta, Ali Aral
doaj   +2 more sources

Essential spectra and exponential estimates of eigenfunctions of lattice operators of quantum mechanics

, 2009
This paper is devoted to estimates of the exponential decay of eigenfunctions of difference operators on the lattice Z^n which are discrete analogs of the Schr\"{o}dinger, Dirac and square-root Klein-Gordon operators.
Agmon S, Agmon S, Albeverio S Lakaev S N Muminov Z I, Ashkroft N W, Basu C, Bjorken S D, Born M, Boykin T B, Buzano E, de Oliveira C R, Deift P, Hislop P D, Jitomirskaya S Ya, Kuchment P, Longhy S, Luckiy Ya A, Madelung O, Martinez A, Martinez A, Mogilner A, Nakamura S, Rabinovich V, Rabinovich V S, Rabinovich V S, Rabinovich V S, Rabinovich V S, Rabinovich V S, Rabinovich V S, Reed M, Reed M, Shubin M A, Stahlhofen A A, Steffen Roch, Taylor M E, Teschl G, Thaller B, Vladimir S Rabinovich, Yafaev D R   +37 more
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On Uniform Exponential Trichotomy in Banach Spaces

Annals of the West University of Timisoara: Mathematics and Computer Science, 2014
In this paper we consider three concepts of uniform exponential trichotomy on the half-line in the general framework of evolution operators in Banach spaces.
Kovacs Monteola Ilona
doaj   +1 more source