TY - JOUR
AU - A. S. Romanyuk
PY - 2009/04/25
Y2 - 2023/03/29
TI - Approximative characteristics of the isotropic classes of periodic functions of many variables
JF - Ukrains’kyi Matematychnyi Zhurnal
JA - Ukr. Mat. Zhurn.
VL - 61
IS - 4
SE - Research articles
DO -
UR - https://umj.imath.kiev.ua/index.php/umj/article/view/3036
AB - 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 from the same classes in the spaces $L_1$ and $L_{∞}$ by trigonometric polynomials with the corresponding spectrum.
ER -