Approximation of classes of periodic functions in one and many variables from the Nikol’skii – Besov and Sobolev spaces

• Date: 2022
• Main Authors: Romanyuk, A. S., Yanchenko, S. Ya., Романюк, А. С., Янченко, С. Я.
• Format: Article
• Language: Ukrainian
• Published: Institute of Mathematics, NAS of Ukraine 2022
• Online Access: https://umj.imath.kiev.ua/index.php/umj/article/view/7141
• Journal Title: Ukrains’kyi Matematychnyi Zhurnal

UDC 517.51 In this paper, we obtain exact-order estimates for the best orthogonal trigonometric approximations of the Nikol'skii-Besov classes $B^{\boldsymbol{r}}_{1,\theta}(\mathbb{T}^d),$ $1\leq\theta\leq\infty,$ of periodic functions of one and many variables with dominating mixed...