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image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Siberian Mathematica...arrow_drop_down
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao
Siberian Mathematical Journal
Article . 1990 . Peer-reviewed
License: Springer Nature TDM
Data sources: Crossref
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao
zbMATH Open
Article . 1990
Data sources: zbMATH Open
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Multiple fourier integral and multiple fourier series under square summation

Multiple Fourier integral and multiple Fourier series under square summation
Authors: Bloshanskij, I. L.;

Multiple fourier integral and multiple fourier series under square summation

Abstract

The author studies a correlation between the convergence of multiple Fourier series and corresponding multiple Fourier integral. For a \(2\pi\)- periodic function f(x), \(x\in R^ N\) with the Fourier decomposition \(\sum_{k}c_ ke^{ikx}\sim f(x),\) let us denote \[ S_ n(x;f)=\sum_{| k_ 1| \leq n_ 1}...\sum_{| k_ N| \leq n_ N}c_ ke^{i(k_ 1x_ 1+...+k_ Nx_ N)},\quad n=(n_ 1,n_ 2,...,n_ N)\in Z^ N, \] and for g(x)\(\sim \int_{R^ N}\hat g(y)e^{i(y,x)}dy\) let us denote \[ J_{\alpha}(x;g)=(2\pi)^{- N}\int^{\alpha_ 1}_{-\alpha_ 1}...\int^{\alpha_ N}_{- \alpha_ N}\hat g(y)e^{i(x,y)}dy,\quad \alpha \in R^ N_+. \] Theorem. There exist functions \(f\in L_ 1([-\pi,\pi]^ N)\), \(g\in L_ 1(R^ N)\), \(N\geq 2\) and for almost every \(x\in [-\pi,\pi]^ N\) there are sequences \(\{n(k,x)\}^{\infty}_{k=1}\) such that 1) \(f(x)=g(x)\), \(x\in [-\pi,\pi]^ N\); 2) (a) \(n(k,x)\in Z^ N\), (b) \(n_ 1(k,x)=n_ 2(k,x)=...=n_ N(k,x)=n_ 0(k,x)\), (c) \(0

Keywords

convergence of multiple Fourier series, Fourier series and coefficients in several variables, multiple Fourier integral, Summability and absolute summability of Fourier and trigonometric series

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selected citations
These citations are derived from selected sources.
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
2
Average
Top 10%
Average
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