Estimates from below for Kolmogorov widths in classes of Poisson integral

• Date: 2013
• Main Authors: Serdyuk, A. S., Bodenchuk, V. V., Сердюк, А. С., Боденчук, В. В.
• Format: Article
• Language: Ukrainian
• Published: Інститут математики НАН України 2013
• Online Access: https://trim.imath.kiev.ua/index.php/trim/article/view/170
• Journal Title: Transactions of Institute of Mathematics of NAS of Ukraine

We expand the ranges of permissible values of $n$ ($n\in\mathbb{N}$) for which Poisson kernels $P_{q,\beta}(t)=\sum\limits_{k=1}^{\infty}q^k\cos\left(kt-\dfrac{\beta\pi}{2}\right)$, ${q\in(0,1)}$, $\beta\in\mathbb{R}$, satisfy Kushpel's condition $C_{y,2n}$. As a consequence, we obtain exac...