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This article is cited in 2 scientific papers (total in 2 papers)
Asymptotic Equalities for Best Approximations for Classes of Infinitely Differentiable Functions Defined by the Modulus of Continuity
A. S. Serdyuk, I. V. Sokolenko Institute of Mathematics, Ukrainian National Academy of Sciences
Abstract:
We obtain asymptotic estimates for best approximations by trigonometric polynomials in the metric of the space $C(L_p)$ for classes of periodic functions expressible as convolutions of kernels $\Psi_\beta$ with Fourier coefficients decreasing to zero faster than any power sequence, and with functions $\varphi\in C$ $(\varphi\in L_p)$ whose moduli of continuity do not exceed the given majorant of $\omega(t)$. It is proved that, in the spaces $C$ and $L_1$, for convex moduli of continuity $\omega(t)$, the obtained estimates are asymptotically sharp.
Keywords:
best approximation by trigonometric polynomials, periodic infinitely differentiable function, modulus of continuity, generalized Poisson kernel, linear approximation method, Kolmogorov–Nikol'skii problem.
Received: 30.10.2012
Citation:
A. S. Serdyuk, I. V. Sokolenko, “Asymptotic Equalities for Best Approximations for Classes of Infinitely Differentiable Functions Defined by the Modulus of Continuity”, Mat. Zametki, 99:6 (2016), 904–920; Math. Notes, 99:6 (2016), 901–915
Linking options:
https://www.mathnet.ru/eng/mzm10189https://doi.org/10.4213/mzm10189 https://www.mathnet.ru/eng/mzm/v99/i6/p904
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