Best Approximations and Widths of Classes of Convolutions of Periodic Functions of High Smoothness

• Datum: 2005
• Hauptverfasser: Serdyuk, A. S., Сердюк, А. С.
• Format: Artikel
• Sprache: Ukrainisch; Englisch
• Veröffentlicht: Institute of Mathematics, NAS of Ukraine 2005
• Online Zugang: https://umj.imath.kiev.ua/index.php/umj/article/view/3655
• Назва журналу: Ukrains’kyi Matematychnyi Zhurnal

We consider classes of $2\pi$-periodic functions that are representable in terms of convolutions with fixed kernels $\Psi_{\overline{\beta}}$ whose Fourier coefficients tend to zero with the exponential rate. We compute exact values of the best approximations of these classes of functions in a uni...