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Włodzimierz Łenski

Publications and source records attributed to Włodzimierz Łenski.

6 recordsLinked to original sources
arXiv2012

Approximation of functions from Lp(w)b by matrix means of their Fourier series

We formulate some special conditions for the integrable functions and moduli of continuity. We give the results on rate of approximation of such functions by matrix means of their Fourier series, where the entries of the rows of the matrix generate the sequences belonging to the classes MRBVS and MHBVS. We also present some results on norm approximation for functions from the generalized integral Lipschitz classes.

math.CA↗
arXiv2012

Strong approximation of almost periodic functions

We consider summability methods generated by the class GM(2b). We generalize some related results of P. Pych-Taberska [Studia Math. XCVI (1990), 91-103] on strong approximation of almost periodic functions by their Fourier series and S. M. Mazhar and V. Totik [J. Approx. Theory, 60(1990), 174-182] on approximation of periodic functions by matrix means of their Fourier series.

math.CA↗
arXiv2012

On some Leindler's theorem on application of the class NMCS

We show the results in the class GM(5b) corresponding to the theorem of L. Leindler [A note on strong approximation of Fourier series, Analysis Mathematica, 29(2003), 195--199] on strong approximation by matrix means of Fourier series constructed by the sequences from the class NMCS.

math.CA↗
arXiv2012

Pointwise strong and very strong approximation by Fourier series of integrable functions

We will present an estimation of the $H_{k_{0},k_{r}}^{q}f$ $\ $and $% H_{u}^{λφ}f$ means as a approximation versions \ of \ the Totik type generalization$(\text{see \cite{11, 12}}) $ \ of the results of \ J. Marcinkiewicz and A. Zygmund in \cite{JM, ZA}. As a measure of such approximations we will use the function constructed on the base of definition of the Gabisonia points \cite{1}. Some results on the norm approximation will also given.

math.CA↗