Some improvements of the Katznelson-Tzafriri theorem on Hilbert space

This paper extends two recent improvements in the Hilbert space setting of the well-known Katznelson-Tzafriri theorem by establishing both a version of the result valid for bounded representations of a large class of abelian semigroups and a quantified version for contractive representations. The pa...

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Detalles Bibliográficos
Autor principal: Seifert, D
Formato: Journal article
Publicado: American Mathematical Society 2015
Descripción
Sumario:This paper extends two recent improvements in the Hilbert space setting of the well-known Katznelson-Tzafriri theorem by establishing both a version of the result valid for bounded representations of a large class of abelian semigroups and a quantified version for contractive representations. The paper concludes with an outline of an improved version of the KatznelsonTzafriri theorem for individual orbits, whose validity extends even to certain unbounded representations.