Best approximations of the classes $B_{p,\,\theta}^{r}$ of periodic functions of many variables in uniform metric

• Date: 2006
• Main Authors: Romanyuk, A. S., Романюк, А. С.
• Format: Article
• Language: Russian; English
• Published: Institute of Mathematics, NAS of Ukraine 2006
• Online Access: https://umj.imath.kiev.ua/index.php/umj/article/view/3541
• Journal Title: Ukrains’kyi Matematychnyi Zhurnal

We obtain estimates exact in order for the best approximations of the classes $B_{\infty,\,\theta}^{r}$ of periodic functions of two variables in the metric of $L_{\infty}$ by trigonometric polynomials whose spectrum belongs to a hyperbolic cross. We also investigate the best approximations of the c...