The estimates bilinear of approximations functions in the space Lorentz

Abstract

In this paper considered Lorentz space of periodic functions of many variables and Nikol’skii’s-Besov’s class. in Lorentz space the definition of the best bilinear of approximation function and Marcinkiewicz-Zygmund theorem for trigonometric polynomial. Is obtained the estimate of the best bilinear of approximation function Nikol’skii’s-Besov’s classes in the space Lorentz.