Spectrum of composition operators on S(R) with polynomial symbols

[EN] We study the spectrum of operators in the Schwartz space of rapidly decreasing functions which associate each function with its composition with a polynomial. In the case where this operator is mean ergodic we prove that its spectrum reduces to {0}, while the spectrum of any non mean ergodic co...

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Bibliographic Details
Authors: Fernández, Carmen, Galbis, Antonio, Jorda Mora, Enrique|||0000-0003-2980-1699
Format: article
Publication Date:2020
Country:España
Institution:Universitat Politècnica de València (UPV)
Repository:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Language:English
OAI Identifier:oai:riunet.upv.es:10251/166135
Online Access:https://riunet.upv.es/handle/10251/166135
Access Level:Open access
Keyword:Composition operator
Space of rapidly decreasing functions
Spectrum
Mean ergodic operator
MATEMATICA APLICADA
Description
Summary:[EN] We study the spectrum of operators in the Schwartz space of rapidly decreasing functions which associate each function with its composition with a polynomial. In the case where this operator is mean ergodic we prove that its spectrum reduces to {0}, while the spectrum of any non mean ergodic composition operator with a polynomial always contains the closed unit disc except perhaps the origin. We obtain a complete description of the spectrum of the composition operator with a quadratic polynomial or a cubic polynomial with positive leading coefficient.