Author:
View More View Less
• 1 College of Sciences, North China University of Technology, Beijing, 100144 China
• 2 School of Mathematical Sciences, Beijing Normal University, Beijing, 100875 China
Restricted access

## Abstract

In this paper, the smallest number M which makes the equality

\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$K_n (W_2^{L_r } (T),MW_2^{L_r } (T),L_2 (T)) = d_n (W_2^{L_r } (T),L_2 (T))$$ \end{document}
valid, is established and the asymptotic order of
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$K_n (W_2^{L_r } (T),W_2^{L_r } (T),L_q (T)),1 \leqslant q \leqslant \infty$$ \end{document}
, is obtained, where
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$W_2^{L_r }$$ \end{document}
(T) is a periodic smooth function class which is determined by a linear differential operator, Kn(·, ·, ·) and dn(·, ·) are the relative width and the width in the sense of Kolmogorov, respectively.

Jul 2020 0 0 0
Aug 2020 1 0 0
Sep 2020 0 0 0
Oct 2020 0 0 0
Nov 2020 0 0 0
Dec 2020 0 0 0
Jan 2021 0 0 0

## Rate of approximation by rectangular partial sums of double orthogonal series

Author: V. A. Andrienko

## Lacunary (0; 0, 1) interpolation on the roots of Jacobi polynomials and their derivatives, respectively. I (Existence, explicit formulae, unicity)

Authors: I. Joó and L. G. Pál