Abstract
General Rogosinsky–Bernstein linear polynomial means \(R_n(f)\) of Fourier series are introduced and three convergence criteria as \(n\to \infty\) are obtained: for convergence in the space \(C\) of continuous periodic functions and for convergence almost everywhere with two guaranteed sets (Lebesgue points and \(d\)-points). For smooth functions, the rate of convergence in norm of \(R_n(f)\), as well as of their interpolation analogues, is also studied. For approximation of functions in \(C^r\), the asymptotics is found along with the rate of decrease of the remainder term.
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References
A. F. Timan, Theory of Approximation of Functions of a Real Variable (Fizmatlit, Moscow, 1960) [in Russian].
N. I. Akhiezer, Lectures in the Theory of Approximation (Nauka, Moscow, 1965) [in Russian].
R. M. Trigub, “The constructive characteristics of certain classes of functions,” Izv. Akad. Nauk SSSR Ser. Mat. 29 (3), 615–630 (1965).
G. A. Fomin, “On linear methods for the summability of Fourier series that are similar to the Bernshtein– Rogosinski method,” Math. USSR-Izv. 1 (2), 319–333 (1967).
R. Trigub, “Norms of linear functionals, summability of trigonometric Fourier series and Wiener algebras,” in Operator Theory and Harmonic Analysis, Springer Proc. in Math. Stat. (Springer, Cham, 2020), Vol. 357, pp. 549–568.
R. M. Trigub and E. S. Belinsky, Fourier Analysis and Approximation of Functions (Kluwer Academic Publ., Dordrecht, 2004).
V. V. Zhuk, Approximation of Periodic Functions (Leningrad, 1982) [in Russian].
R. M. Trigub, “On various moduli of smoothness and \(K\)-functionals,” Ukrainian Math. J. 72 (7), 1131–1163 (2020).
A. Zygmund, Trigonometric Series (Cambridge Univ. Press, Cambridge, 1959, 1960), Vols. 1–2.
F. Dai, A. Prymak, V. N. Temlyakov, and S. Yu. Tikhonov, “Integral norm discretization and related problems,” Russian Math. Surveys 74 (4), 579–630 (2019).
R. M. Trigub, “Asymptotics of approximation of continuous periodic functions by linear means of their Fourier series,” Izv. Math. 84 (3), 608–624 (2020).
R. M. Trigub, “Almost everywhere summability of Fourier series with indication of the set of convergence,” Math. Notes 100 (1), 139–153 (2016).
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Translated from Matematicheskie Zametki, 2022, Vol. 111, pp. 592-605 https://doi.org/10.4213/mzm13450.
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Trigub, R.M. Rogosinsky–Bernstein Polynomial Method of Summation of Trigonometric Fourier Series. Math Notes 111, 604–615 (2022). https://doi.org/10.1134/S0001434622030294
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DOI: https://doi.org/10.1134/S0001434622030294
Keywords
- series and Fourier transforms
- Hardy’s inequality
- Riesz means
- Lebesgue points (\(l\)-points) and \(d\)-points
- modulus of smoothness
- linearized modulus of smoothness
- Jackson’s theorem
- Vallée-Poussin polynomial
- conjugate function
- entire functions of exponential type
- comparison principle
- Marcinkiewicz’s inequality and discretization