Order estimates of the best approximations and approximations of Fourier sums of classes of convolutions of periodic functions of not high smoothness in uniform metric (1403.5311v1)

Abstract: We obtain exact for order estimates of best uniform approximations and uniform approximations by Fourier sums of classes of convolutions the periodic functions belong to unit balls of spaces $L_{p}, \ {1\leq p<\infty}$, with generating kernel $\Psi_{\beta}$, whose absolute values of Fourier coefficients $\psi(k)$ are such that $\sum\limits_{k=1}^{\infty}\psi^{p'}(k)k^{p'-2}<\infty$, $\frac{1}{p}+\frac{1}{p'}=1$, and product $\psi(n)n^{\frac{1}{p}}$ can't tend to nought faster than power functions.