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Extended Levett trigonometric series. [PDF]

open access: yesPLoS ONE
An extension of two finite trigonometric series is studied to derive closed form formulae involving the Hurwitz-Lerch zeta function. The trigonometric series involves angles with a geometric series involving the powers of 3.
Robert Reynolds
doaj   +5 more sources

Approximation on the regular hexagon

open access: yesJournal of Numerical Analysis and Approximation Theory, 2020
The degree of trigonometric approximation of continuous functions, which are periodic with respect to the hexagon lattice, is estimated in uniform and Hölder norms.
Ali Guven
doaj   +7 more sources

Best approximation by «angle» and the absolute Cesàro summability of double Fourier series

open access: yesҚарағанды университетінің хабаршысы. Математика сериясы, 2023
This article is devoted to the topic of absolute summation of series or Cesaro summation. The relevance of this article lies in the fact that a type of absolute summation with vector index which has not been previously studied is considered.
S. Bitimkhan, O. Mekesh
doaj   +1 more source

Integrated Geometric Optimal Control of Spacecraft Attitude and Orbit Based on SE(3)

open access: yesIEEE Access, 2023
A model predictive convex programming (MPCP) on $SE(3)$ parametrized by trigonometric series control is proposed in this paper, to solve the optimal control problem of spacecraft attitude orbit integration.
Zhongzhong Zheng   +4 more
doaj   +1 more source

Partial best approximations and the absolute Cesaro summability of multiple Fourier series

open access: yesҚарағанды университетінің хабаршысы. Математика сериясы, 2021
The article is devoted to the problem of absolute Cesaro summability of multiple trigonometric Fourier series. Taking a central place in the theory of Fourier series this problem was developed quite widely in the one-dimensional case and the fundamental
S. Bitimkhan, D.T. Alibieva
doaj   +1 more source

Inequalities for finite trigonometric sums. An interplay: with some series related to harmonic numbers

open access: yesJournal of Inequalities and Applications, 2016
An interplay between the sum of certain series related to harmonic numbers and certain finite trigonometric sums is investigated. This allows us to express the sum of these series in terms of the considered trigonometric sums, and permits us to find ...
Omran Kouba
doaj   +1 more source

Rearrangements of Trigonometric Series and Trigonometric Polynomials [PDF]

open access: yesReal Analysis Exchange, 2004
The paper is related to the following question of P.~L.~Ul'yanov: is it true that for any $2π$-periodic continuous function $f$ there is a uniformly convergent rearrangement of its trigonometric Fourier series? In particular, we give an affirmative answer if the absolute values of Fourier coefficients of $f$ decrease.
openaire   +3 more sources

Hardy-Littlewood theorem for series with general monotone coefficients

open access: yesҚарағанды университетінің хабаршысы. Математика сериясы, 2018
In this work we study trigonometric series with general monotone coefficients. Also, we consider Lqϕ ( Lq ) space. In particular, when ϕ ( t ) ≡ 1 the space Lqϕ ( Lq ) coincides with Lq .
S. Bitimkhan
doaj   +1 more source

A new note on factored infinite series and trigonometric Fourier series

open access: yesComptes Rendus. Mathématique, 2021
In this paper, we have proved two main theorems under more weaker conditions dealing with absolute weighted arithmetic mean summability factors of infinite series and trigonometric Fourier series.
Bor, Hüseyin
doaj   +1 more source

Dual Trigonometrical Series [PDF]

open access: yesProceedings of the Glasgow Mathematical Association, 1959
In a recent joint paper with J. C. Cooke [1], we have given a method of determining the coefficients an in the “dual” Fourier-Bessel serieswhere −1 ≤p≤, F(r) is specified and αn is a positive root of Jv(αnα) = 0. This method reduced the problem to the solution of an infinite set of algebraical equations and it was shown that, under certain ...
openaire   +1 more source

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