摘要
According to results established by DeLeeuw-Rudin-Wermer and by Forelli, all linear isometries of any Hardy space H p (p ? 1, p ≠ = 2) on the open unit disc Δ of ? are represented by weighted composition operators defined by inner functions on Δ. After reviewing (and completing when p = ∞) some of those results, the present report deals with a characterization of periodic and almost periodic semigroups of linear isometries of H p .
According to results established by DeLeeuw-Rudin-Wermer and by Forelli,all linear isometries of any Hardy space H^p(p≥1,p≠2)on the open unit discΔof C are represented by weighted composition operators defined by inner functions onΔ.After reviewing(and completing when p=∞)some of those results,the present report deals with a characterization of periodic and almost periodic semigroups of linear isometries of H^p.
