Exact values of mean $n$-widths for the classes of functions analytic in the upper half plane in the Hardy space

Abstract

In the Hardy space $H_2 ℝ_+^2$ of functions analytic in the upper half plane such that $$\sup \left\{ {\int\limits_\mathbb{R} {|f(x + iy)|^2 dx: 0< y< \infty } } \right\}< \infty ,$$ we determine mean $N$-widths and find their exact values for numerous classes of functions.