$K$-functionals and extreme problems of the theory of approximation for classes of analytic functions in the circle. I

  • S. B. Vakarchuk Alfred Nobel University, Dnipro
  • M. B. Vakarchuk Oles Honchar Dnipro National University

Abstract

УДК 517.5

Based on the Hadamard composition in the Hardy, Bergman and Gvaradze Banach spaces of functions analytic in the unit circle, we consider a generalization of the $K$-functional. In solving some extreme problems of the theory of approximation in the complex plane, we obtain certain exact results in the case where the indicated $K$-functional is used as a  characteristic of smoothness. 

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Published
31.05.2022
How to Cite
Vakarchuk, S. B., and M. B. Vakarchuk. “$K$-Functionals and Extreme Problems of the Theory of Approximation for Classes of Analytic Functions in the Circle. I”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 74, no. 4, May 2022, pp. 469 -85, doi:10.37863/umzh.v74i4.6980.
Section
Research articles