Abstract
© 2019 Russian Academy of Sciences (DoM), London Mathematical Society, Turpion Ltd. We consider functions represented as trigonometric series with general monotone Fourier coefficients. The main result of the paper is the equivalence of the Lp modulus of smoothness, 1 < p < ∞, of such functions to certain sums of their Fourier coefficients. As applications, for such functions we give a description of the norm in the Besov space and sharp direct and inverse theorems in approximation theory.
Original language | English |
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Pages (from-to) | 994-1018 |
Number of pages | 25 |
Journal | Sbornik Mathematics |
Volume | 210 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jul 2019 |
Keywords
- CONTINUITY
- Fourier series
- L-P
- MODULI
- MONOTONICITY
- TRANSFORMS
- TRIGONOMETRIC SERIES
- general monotone sequences
- moduli of smoothness