Abstract:
In this paper, we prove direct and inverse theorems on the approximation of functions by Fourier–Laplace sums in the spaces S(p,q)(σm−1), m⩾3, in terms of best approximations and moduli of continuity and consider the constructive characteristics of function classes defined by the moduli of continuity of their elements. The given statements generalize the results of the author's work carried out in 2007.
Keywords:
approximation of functions, Fourier–Laplace sum, the spaces S(p,q)(σm−1), modulus of continuity, Parseval's equality, Jackson-type inequality, Gegenbauer polynomial, Bernstein–Stechkin–Timan-type inequality.
Citation:
R. A. Lasuriya, “Direct and Inverse Theorems on the Approximation of Functions by Fourier–Laplace Sums in the Spaces S(p,q)(σm−1)”, Mat. Zametki, 98:4 (2015), 530–543; Math. Notes, 98:4 (2015), 601–612
\Bibitem{Las15}
\by R.~A.~Lasuriya
\paper Direct and Inverse Theorems on the Approximation of Functions by Fourier--Laplace Sums in the Spaces $S^{(p,q)}(\sigma^{m-1})$
\jour Mat. Zametki
\yr 2015
\vol 98
\issue 4
\pages 530--543
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\crossref{https://doi.org/10.4213/mzm10175}
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\transl
\jour Math. Notes
\yr 2015
\vol 98
\issue 4
\pages 601--612
\crossref{https://doi.org/10.1134/S0001434615090278}
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Linking options:
https://www.mathnet.ru/eng/mzm10175
https://doi.org/10.4213/mzm10175
https://www.mathnet.ru/eng/mzm/v98/i4/p530
This publication is cited in the following 4 articles:
R. A. Lasuriya, “On Quantities of the Type of Modulus of Continuity and Analogs of K-Functionals in the Spaces S(p,q)(σm−1)”, Math. Notes, 113:2 (2023), 255–266
El Ouadih S., Daher R., Tyr O., Saadi F., “Equivalence of K-Functionals and Moduli of Smoothness Generated By the Beltrami-Laplace Operator on the Spaces S-(P,S-Q)(SIGMA(M-1))”, Rend. Circ. Mat. Palermo, 71:1 (2022), 445–458
R. A. Lasuriya, “Inverse Approximation Theorems in the Spaces S(p,q)(σm−1)”, Math. Notes, 110:1 (2021), 80–91
R. A. Lasuriya, “Jackson-Type Inequalities in the Spaces S(p,q)(σm−1)”, Math. Notes, 105:5 (2019), 707–719