Lower bounds for Kolmogorov widths in classes of convolutions with Neumann kernel

• Datum: 2014
• Hauptverfasser: Bodenchuk, V. V., Боденчук, В. В.
• Format: Artikel
• Sprache: Ukrainisch
• Veröffentlicht: Інститут математики НАН України 2014
• Online Zugang: https://trim.imath.kiev.ua/index.php/trim/article/view/15
• Назва журналу: Transactions of Institute of Mathematics of NAS of Ukraine

We obtain exact lower bounds for Kolmogorov $n$-widths in spaces $C$ and $L$ of classes of convolutions with Neumann kernel $N_{q,\beta}(t)=\sum\limits_{k=1}^{\infty}\dfrac{q^k}{k}\cos\left(kt-\dfrac{\beta\pi}{2}\right)$, ${q\in(0,1)}$, ${\beta\in\mathbb{R}}$, for all natural $n$ greater some number...