Results 251 to 260 of about 62,545 (283)

Multipliers of Fourier series

Ukrainian Mathematical Journal, 1991
Let \(S\) be a nonempty set of integers, and let \(C_ S(T)\) be a subspace of those \(f\) of \(C(T)\), \(T=(-\pi,\pi]\) whose spectrum is in \(S\), i.e., \(\{k:\hat f(k)\neq 0\}\subset S\). The paper deals with new propositions for multipliers of trigonometrical Fourier series in the spaces \(C(T)\) and \(C_ S(T)\).
openaire   +2 more sources

Multipliers of the fourier-haar series

Siberian Mathematical Journal, 2000
The Haar system on \((0,1)\) is defined by the following equalities: \(\chi_0^0(t)=1\), \(\chi_n^k(t)=2^{n/2}\) for \(t\in ((k-1)2^{-n},(k-1/2)2^{-n})\), \(\chi_n^k(t)=-2^{n/2}\) for \(t\in ((k-1/2)2^{-n},k2^{-n})\), and \(\chi_n^k(t)=0\) for the remaining values of \(t\in (0,1)\), where \(1\leq k\leq 2^n\) and \(n=0,1,\dots\;\).
Bryskin, I. B., Lelond, O. V., Semenov, E. M.   +2 more
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Operator Valued Fourier Multipliers

1999
Results on Fourier multipliers are important tools in the study of partial differential equations. They represent a major step, for example, when establishing a priori estimates for solutions of parabolic evolution equations of Agmon-Douglis-Nirenberg type [1].
openaire   +1 more source

WEYL MULTIPLIERS FOR MULTIPLE FOURIER SERIES

Mathematics of the USSR-Sbornik, 1972
In this paper Weyl multipliers for a multiple series in an arbitrary orthogonal system are found when the multiplier is known for the one-dimensional series. Bibliography: 7 items.
openaire   +1 more source

Absolute Fourier multipliers

Results in Mathematics, 1981
Edwards, R. E., Helson, H.
openaire   +2 more sources

Fourier multipliers via twisted convolution

Proceedings of the American Mathematical Society
We study L p → L q L^p \to L^q boundedness of Fourier multipliers on R 2 n {\mathbb {R}}^{2n} , which arise as twisted convolution of functions from Lebesgue spaces.
Maity, Arup Kumar, Ratnakumar, P. K.
openaire   +1 more source

Variation, homeomorphisms, and Fourier multipliers

Comptes Rendus de l'Académie des Sciences - Series I - Mathematics, 1997
An \(L^\infty\) function on the circle \(\mathbb T\) is called a Fourier multiplier in \(l^p\), \(1\leq p\leq \infty\), if the linear operator \(u\to (f\cdot \check u)^\wedge\) is bounded in \(l^p\). The class of all such multipliers is denoted by \(\mathbb M^p(\mathbb T)\).
openaire   +1 more source

Fourier Multipliers

2004
Roald M. Trigub, Eduard S. Bellinsky
openaire   +1 more source

Leibniz-Type Rules for Bilinear Fourier Multiplier Operators with Besov Regularity

Results in Mathematics, 2021
Xinfeng Wu, Jiexing Yang
exaly  

Leibniz-Type Rules for Bilinear and Biparameter Fourier Multiplier Operators with Applications

Potential Analysis, 2020
Jiexing Yang, Xinfeng Wu
exaly