Abstract
An asymptotic equality is found for the lower bounds of the best approximations of the classes C ψβ ,∞ under a condition of slow growth of ψ(·).
Literature cited
A. I. Stepanets, Classes of Periodic Functions and Approximations of Their Elements by Fourier Sums [in Russian], Preprint 83.10, Akad. Nauk UkrSSR Inst. Mat., Kiev (1983).
A. I. Stepanets, Classification and Approximation of Periodic Functions [in Russian], Naukova Dumka, Kiev (1987).
S. A. Telyakovskii, “On norms of trigonometric polynomials and approximations of differentiable functions by linear means of their Fourier series. I,” Tr. Mat. Inst. Akad. Nauk SSSR,62, 61–97 (1961).
D. N. Bushev, Approximation of Classes of Continuous Periodic Functions by Zygmund Sums [in Russian], Preprint 84.56, Akad. Nauk UkrSSR Inst. Mat., Kiev (1984).
S. A. Telyakovskii, “On the approximation of functions of given classes by Fourier sums,” Theory of Functions and Approximations [in Russian], Tr. III Sarat. Zim. Shkoly, 27 Jan.–7th Feb., 1986, Mezhvuz. Nauch. Sb., Part 1, Sarat. Univ., Saratov (1987).
S. A. Telyakovskii, “On norms of trigonometric polynomials and approximation of differentiable functions by linear means of their Fourier series. II,“ Izv. Akad. Nauk SSSR, Ser Mat.,27, No. 2, 253–272 (1963).
A. I. Stepanets, “Fourier sums: new results and unsolved problems,” Ukr. Mat. Zh.,40, No. 5, 547–576 (1988).
N. P. Korneichuk, Extremal Problems in Approximation Theory [in Russian], Nauka, Moscow (1976).
Author information
Authors and Affiliations
Additional information
Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 42, No. 3, pp. 406–412, March, 1990.
Rights and permissions
About this article
Cite this article
Bushev, D.N., Stepanets, A.I. Approximation of weakly differentiable periodic functions. Ukr Math J 42, 361–366 (1990). https://doi.org/10.1007/BF01057026
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01057026