Results 1 to 10 of about 33 (27)
APPROXIMATION OF DIFFERENTIATION OPERATORS BY BOUNDED LINEAR OPERATORS IN LEBESGUE SPACES ON THE AXIS AND RELATED PROBLEMS IN THE SPACES OF \((p,q)\)-MULTIPLIERS AND THEIR PREDUAL SPACES [PDF]
Ural Mathematical Journal, 2023 We consider a variant \(E_{n,k}(N;r,r;p,p)\) of the four-parameter Stechkin problem \(E_{n,k}(N;r,s;p,q)\) on the best approximation of differentiation operators of order \(k\) on the class of \(n\) times differentiable functions ...
Vitalii V. Arestov
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APPROXIMATION OF ONE CLASS OF SMOOTH FUNCTIONS BY ANOTHER CLASS OF SMOOTHER FUNCTIONS ON THE AXIS [PDF]
Ural Mathematical JournalThis paper investigates the problem of best and best linear approximation in the space of functions on the real axis with bounded Fourier transform. The study focuses on approximating the class \(B_1^{n-k}(1)\) of functions whose derivatives of order \(n-
Vitalii V. Arestov
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Weighted sparsity and sparse tensor networks for least squares approximation [PDF]
, 2023 Approximation of high-dimensional functions is a problem in many scientific fields that is only feasible if advantageous structural properties, such as sparsity in a given basis, can be exploited.
Trunschke, Philipp +2 more
core +6 more sources
On Landau-Kolmogorov type inequalities for charges and their applications
Researches in Mathematics, 2023 In this article we prove sharp Landau-Kolmogorov type inequalities on a class of charges defined on Lebesgue measurable subsets of a cone in $\mathbb{R}^d$, $d\geqslant 1$, that are absolutely continuous with respect to the Lebesgue measure.
V.F. Babenko +3 more
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Effect of Rotation Speed and Flow Rate on Slip Factor in a Centrifugal Pump
Shock and Vibration, Volume 2021, Issue 1, 2021., 2021 This work analyzes the causes of the slip phenomenon in the impeller on the basis of the internal flow mechanism. Detailed optical measurements of the flow inside the rotation passages of a five‐bladed centrifugal pump impeller are obtained through particle image velocimetry (PIV).
Bo Chen +7 more
wiley +1 more source
Numerical Functional Analysis and Optimization, 2023 We prove an analogue of the Korneichuk--Stechkin lemma for functions with values in $L$-spaces. As applications, we obtain sharp Ostrowski type inequalities and solve problems of optimal recovery of identity and convexifying operators, as well as the problem of integral recovery, on the classes of $L$-space valued functions with given majorant of ...
Vladyslav Babenko +2 more
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Stechkin’s problem for differential operators and functionals of first and second orders
Journal of Approximation Theory, 2013 In this paper, we present the solution to Stechkin’s problem for differential operators and functionals of first and second orders on the class of functions that are defined on a finite interval and have bounded third derivative. Two related problems are discussed: (1) finding sharp constants in the Landau–Kolmogorov inequalities, and (2) optimal ...
Babenko, Yuliya, Skorokhodov, Dmitriy
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ON THE BEST APPROXIMATION OF THE DIFFERENTIATION OPERATOR
Ural Mathematical Journal, 2015 In this paper we give a solution of the problem of the best approximation in the uniform norm of the differentiation operator of order k by bounded linear operators in the class of functions with the property that the Fourier transforms of their ...
Vitalii V. Arestov
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Mathematical Notes, 2012 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Babenko, Yu. V., Skorokhodov, D. S.
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О сопряженности пространства мультипликаторов [PDF]
, 2019 A. Figà Talamanca proved (1965) that the space Mr = Mr(G) of bounded linear operators in the space Lr, 1 ≤ r ≤ ∞, on a locally compact group G that are translation invariant (more exactly, invariant under the group operation) is the conjugate space for a
Arestov, V. V.
core +1 more source