Approximative characteristics of the isotropic classes of periodic functions of many variables

• Datum: 2009
• Hauptverfasser: Romanyuk, A. S., Романюк, А. С.
• Format: Artikel
• Sprache: Russisch; Englisch
• Veröffentlicht: Institute of Mathematics, NAS of Ukraine 2009
• Online Zugang: https://umj.imath.kiev.ua/index.php/umj/article/view/3036
• Назва журналу: Ukrains’kyi Matematychnyi Zhurnal

Exact-order estimates are obtained for the best orthogonal trigonometric approximations of the Besov $(B_{p,θ}^r)$ and Nukol’skii $(H_p^r )$ classes of periodic functions of many variables in the metric of $L_q , 1 ≤ p, q ≤ ∞$. We also establish the orders of the best approximations of functions fro...