Best Linear Methods of Approximation of Functions of the Hardy Class $H_p$
We determine the exact value of the best linear polynomial approximation of a unit ball of the Hardy space $H_p, 1 ≤ p ≤ ∞$, on concentric circles $Tρ = z ∈ C:|z|=ρ, 0 ≤ ρ < 1$, in the uniform metric. We construct the best linear method of approximation and prove the uniqueness of this method.
English version (Springer): Ukrainian Mathematical Journal 55 (2003), no. 7, pp 1110–1118.
Citation Example: Savchuk V. V. Best Linear Methods of Approximation of Functions of the Hardy Class $H_p$ // Ukr. Mat. Zh. - 2003. - 55, № 7. - pp. 919-925.