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On conjugate rational trigonometric Fourier series and their approximation properties

Abstract

The article considers conjugate rational trigonometric Fourier series. An integral representation of their partial sums and the Dini test for the convergence of the given series were obtained. The approximation of functions conjugate to $|\sin x|^s$, $s>0$ by partial sums of conjugate rational trigonometric Fourier series is investigated. An integral representation, uniform and point estimates for the above-mentioned approximation were obtained. On the base of the uniform estimate polynomial, a fixed number of geometrically different poles, and general cases were studied.

About the Authors

N. Ju. Kazlouskaya
Yanka Kupala State University of Grodna
Belarus


Ya. A. Rovba
Yanka Kupala State University of Grodna
Belarus


References

1. Young W. H. Konvergenzbedingunger fur die verwandte Reihe einer Fourierschen Reihe // Munchener Sitzungsberichte. 1911. Vol. 41. P. 261–371.

2. Бари Н. К. Тригонометрические ряды. М.: Физматгиз, 1961.

3. Китбалян А. А. Разложения по обобщенным тригонометрическим системам // Изв. АН Арм. ССР. Сер. физ.-мат. наук. 1956. Т. 16, № 6. С. 3–24.

4. Джрбашян М. М. К теории рядов Фурье по рациональным функциям // Изв. АН Арм. ССР. Сер. физ.-мат. наук. 1956. Т. 9, № 7. С. 3–28.

5. Ахиезер Н. И. Лекции по теории аппроксимации. М.: Наука, 1965.

6. Гахов Ф. Д. Краевые задачи. М.: Наука, 1977.

7. Казлоўская Н. Ю., Роўба Я. А. Аб апраксімацыі функцыі | sin x |<sup>s</sup> частковымі сумамі трыганаметрычных рацыянальных шэрагаў Фур’е // Доклады Нац. акад. наук Беларуси. 2021. Т. 65, № 1. С. 11–17.

8. Эрдейи А. Асимптотические разложения. М.: Физматгиз, 1962.


Review

For citations:


Kazlouskaya N.J., Rovba Ya.A. On conjugate rational trigonometric Fourier series and their approximation properties. Trudy Instituta matematiki. 2023;31(1):58-69. (In Russ.)

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ISSN 1812-5093 (Print)