
doi: 10.2307/2045025
Let there be given finitely many points \(\{\alpha_ k\}^ n_ 1\) from the unit disc. If f is a \(H^ p\)-function then how well can the value of f at \(z=0\) be approximated by linear means \(\sum^{n}_{1}c_ kf(\alpha_ k)?\) We give the optimal constants \(c_ k\) and get, as a corollary, the possibility of the approximation of f by operators of the form \(\sum^{n}_{1}f(\alpha_ k)p_ k\) with polynomials \(p_ k\). The order of approximation depends on the distance \(\sum^{n}_{1}(1- | \alpha_ k|)\) of the point system from the unit circle.
recovery, order of approximation, disk algebra, \(H^p\)-classes, \(H^p\)-spaces
recovery, order of approximation, disk algebra, \(H^p\)-classes, \(H^p\)-spaces
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