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Related papers: Strong approximation of almost periodic functions

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We show that on almost complex surfaces plurisubharmonic functions can be locally approximated by smooth plurisubharmonic functions. The main tool is the Poletsky type theorem due to U. Kuzman.

Complex Variables · Mathematics 2014-03-10 Szymon Pliś

It is proved a BMO-estimation for quadratic partial sums of two-dimensional Walsh-Fourier series from which it is derived an almost everywhere exponential summability of quadratic partial sums of double Walsh-Fourier series.

Analysis of PDEs · Mathematics 2016-05-24 Ushangi Goginava

In this paper, sufficient conditions for the existence of trigonometric Hermite-Jacobi appro\-ximations of a system of functions that are sums of convergent Fourier series are found. Based on these results, sufficient conditions are…

Classical Analysis and ODEs · Mathematics 2025-10-10 A. P. Starovoitov , I. V. Kruglikov

In this paper, we introduce several various classes of $c$-almost periodic type functions and their Stepanov generalizations, where $c\in {\mathbb C}$ and $|c|=1.$ We also consider the corresponding classes of $c$-almost periodic type…

Functional Analysis · Mathematics 2020-05-25 M. T. Khalladi , M. Kostić , M. Pinto , A. Rahmani , D. Velinov

In this paper, we analyze multi-dimensional quasi-asymptotically $c$-almost periodic functions and their Stepanov generalizations as well as multi-dimensional Weyl $c$-almost periodic type functions. We also analyze several important…

Functional Analysis · Mathematics 2021-03-31 Marko Kostić

In this short note we show the equivalence of Fourier expansion and Poisson summation approaches for the series approximation of the exponential function $\exp ({-{t^2}/4})$. The application of the Poisson summation formula is shown to…

Classical Analysis and ODEs · Mathematics 2019-04-26 S. M. Abrarov , B. M. Quine , R. K. Jagpal

This paper uses the machinery of almost periodic functions to prove that even without uniform convergence the connection between a pair of almost periodic functions and the constants of the associated Fourier series exists for both the…

Number Theory · Mathematics 2015-07-29 John Washburn

In this paper, we provide strong $L_2$-rates of approximation of the integral-type functionals of Markov processes by integral sums. We improve the method developed in [2]. Under assumptions on the process formulated only in terms of its…

Probability · Mathematics 2015-08-13 Iurii Ganychenko

In this paper, approximation by means of algebraic polynomials of classes of functions defined by a generalised modulus of smoothness of operators of differentiation of these functions is considered. We give structural characteristics of…

Functional Analysis · Mathematics 2012-08-28 Nimete Sh. Berisha , Faton M. Berisha

It is common in functional data analysis to look at a set of related functions: a set of learning curves, a set of brain signals, a set of spatial maps, etc. One way to express relatedness is through an additive model, whereby each…

Computation · Statistics 2014-02-21 Simon Barthelme

The aim of this paper is to apply an original computation method due to Malesevic and Makragic [5] to the problem of approximating some trigonometric functions. Inequalities of Wilker-Cusa-Huygens are discussed, but the method can be…

Classical Analysis and ODEs · Mathematics 2019-10-15 Marija Nenezic , Branko Malesevic , Cristinel Mortici

In this paper, we analyze metrical approximations of functions $F :\Lambda times X \rightarrow Y$ by trigonometric polynomials and $\rho$-periodic type functions, where $\emptyset \neq \Lambda \subseteq {\mathbb R}^{n},$ $X$ and $Y $are…

Functional Analysis · Mathematics 2022-05-19 B. Chaouchi , M. Kostic , D. Velinov

We present a new method for approximating real-valued functions on ${\mathbb R}^+$ by linear combinations of exponential functions with complex coefficients. The approach is based on a multi-point Pad\'e approximation of the Laplace…

Numerical Analysis · Mathematics 2026-05-05 Alexey Kuznetsov , Armin Mohammadioroojeh

Let $S_\lambda F(x)$ be the spherical partial sums of the multiple Fourier series of function $F\in L_2(\mathbb{T}^N)$. We prove almost-everywhere convergence $S_\lambda F(x)\rightarrow F(x)$ for functions in Sobolev spaces…

Analysis of PDEs · Mathematics 2020-01-22 Ravshan Ashurov

We consider composite functions in the elementary algebraic framework. Without any use of the Fourier transform, we find almost periodic orbits which suitably characterizes certain composite functions. In particular, we provide special…

Machine Learning · Computer Science 2025-06-17 Chikara Nakayama , Tsuyoshi Yoneda

Based on Bohr's equivalence relation which was established for general Dirichlet series, in this paper we introduce a new equivalence relation on the space of almost periodic functions in the sense of Besicovitch,…

Functional Analysis · Mathematics 2018-02-01 J. M. Sepulcre , T. Vidal

We give an extension of Bochner's criterion for the almost periodic functions. By using our main result, we extend two results of A. Haraux. The first is a generalization of Bochner's criterion which is useful for periodic dynamical…

Classical Analysis and ODEs · Mathematics 2023-01-03 Philippe Cieutat

In some applications, one is interested in reconstructing a function $f$ from its Fourier series coefficients. The problem is that the Fourier series is slowly convergent if the function is non-periodic, or is non-smooth. In this paper, we…

Numerical Analysis · Mathematics 2020-04-14 David Levin

We establish two general theorems on the local properties of the absolute summability of factored Fourier series by applying a recently defined absolute summability, $\left\vert A,\alpha_{n}\right\vert _{k}$ summability, and the class…

Analysis of PDEs · Mathematics 2013-01-30 Hüseyin Bor , Dansheng Yu , Ping Zhou

We present a survey of results related to the solution of Kolmogorov--Nikolsky problem for Fourier sums on the classes of generalized Poisson integrals $C^{\alpha,r}_{\beta,p}$, which consists in finding of asymptotic equalities for exact…

Classical Analysis and ODEs · Mathematics 2024-09-18 Anatoly Serdyuk , Tetiana Stepaniuk