Article ID Journal Published Year Pages File Type
4582501 Expositiones Mathematicae 2009 16 Pages PDF
Abstract

Given any space of holomorphic functions in the open unit disc DD, satisfying certain conditions, we characterize the self-mappings of its algebraic dual space which preserve the set of all evaluation functionals δzδz. Among these maps, we give a description of those which contract the norm and those which preserve it. In the case where the norm ∥δz∥∥δz∥ depends strictly increasingly on |z||z|, we show that the first ones arise exactly from the self-maps of DD vanishing at 0. When this dependence is only injective, we prove that the second ones are precisely induced by the rotations of DD. We provide a nice generalization of those results in the case where ∥δz∥∥δz∥ grows with |θ(z)||θ(z)|, for a given automorphism θθ of DD.

Related Topics
Physical Sciences and Engineering Mathematics Algebra and Number Theory
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