Results 21 to 30 of about 2,695 (277)
On the adjoint of a symmetric operator [PDF]
, 2007 In general it is a non-trivial task to determine the adjoint S* of an unbounded symmetric operator S in a Hilbert or Krein space. We propose a method to specify S* explicitly which makes use of two boundary mappings that satisfy an abstract Green's ...
Meda S. +47 more
core +4 more sources
On linear chaos in function spaces
Demonstratio Mathematica, 2022 We show that, in Lp(0,∞){L}_{p}\left(0,\infty ) (1 ...
Jimenez John M., Markin Marat V.
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An implicit division of bounded and unbounded linear operators which preserves their properties [PDF]
Glasnik matematički, 2011 We give an answer to the following problem: Given two linear operators A and B such that BA and A verify some property P, then when does B verify the same property P? Of course, we have to assume that B satisfies some condition Q independent of (or weaker than) P.
Mortad, Mohammed Hichem +1 more
openaire +4 more sources
Many bounded versions of undecidable problems are NP-hard
SciPost Physics, 2023 Several physically inspired problems have been proven undecidable; examples are the spectral gap problem and the membership problem for quantum correlations.
Andreas Klingler, Mirte van der Eyden, Sebastian Stengele, Tobias Reinhart, Gemma de las Cuevas
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On Hahn-Banach theorem and some of its applications
Open Mathematics, 2022 First, this work provides an overview of some of the Hahn-Banach type theorems. Of note, some of these extension results for linear operators found recent applications to isotonicity of convex operators on a convex cone.
Olteanu Octav
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Invertibility and Fredholm Property of Fock Toeplitz Operators
Mathematics, 2023 We characterize some necessary and sufficient conditions of invertible Toeplitz operators acting on the Fock space. In particular, we study the Fredholm properties of Toeplitz operators with BMO1 symbols, where their Berezin transforms are bounded ...
Chunxu Xu, Tao Yu
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Estimates for the Differences of Certain Positive Linear Operators
Mathematics, 2020 The present paper deals with estimates for differences of certain positive linear operators defined on bounded or unbounded intervals. Our approach involves Baskakov type operators, the kth order Kantorovich modification of the Baskakov operators, the ...
Ana Maria Acu, Sever Hodiş, Ioan Rașa
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The Perturbations of Weyl’s Theorems for Unbounded Class-A Operators
Journal of Kufa for Mathematics and Computer, 2023 The significance of Weyl's spectrum is regional to the perturbation theory but recently it is related to operator theory in some theorems. The study of Weyl’s theorem has so far limited to the class of bounded operators, however, lately this study has ...
Dalia Sami Ali, Buthainah A. Ahmed
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Theory of B(X)-Module: Algebraic Module Structure of Generally Unbounded Infinitesimal Generators
Advances in Mathematical Physics, 2020 The concept of logarithmic representation of infinitesimal generators is introduced, and it is applied to clarify the algebraic structure of bounded and unbounded infinitesimal generators.
Yoritaka Iwata
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Rate of Convergence for a New Family of Summation-Integral Beta Operators [PDF]
المجلة العراقية للعلوم الاحصائية, 2011 In the present paper, we define a new family of summation-integral Beta operators to approximate a class of unbounded continuous functions of polynomial growth , for some and then we estimate the rate of convergence for this family for functions have ...
Ali J. Mohammad and Ansam A. Abdul-Rahman
doaj +1 more source