Approximation of classes of analytic functions by algebraic polynomials and kolmogorov widths

• Date: 1996
• Main Authors: Romanyuk, V. S., Романюк, В. С.
• Format: Article
• Language: Russian; English
• Published: Institute of Mathematics, NAS of Ukraine 1996
• Online Access: https://umj.imath.kiev.ua/index.php/umj/article/view/5351
• Journal Title: Ukrains’kyi Matematychnyi Zhurnal

We obtain estimates of the best polynomial approximations, uniform in the closure $B$ of Faber domains of the complex plane $ℂ$, for functions continuous in $B$ and defined by Cauchy-type integrals with densities possessing certain generalized differential properties. We establish estimates exact in...