Operators acting in the dual spaces of discrete Cesàro spaces

[EN] The discrete Cesaro (Banach) sequence spaces ces(r),1<r<infinity, have been thoroughly investigated for over 45 years. Not so for their dual spaces d(s) approximately equal to (ces(r))', which are somewhat unwieldy. Our aim is to undertake a further study of the spaces d(...

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Detalles Bibliográficos
Autores: Bonet Solves, José Antonio|||0000-0002-9096-6380, RICKER, WERNER
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglés
OAI Identifier:oai:riunet.upv.es:10251/161155
Acceso en línea:https://riunet.upv.es/handle/10251/161155
Access Level:acceso abierto
Palabra clave:Banach sequence space
Cesaro operator
Regular operator
Multiplier
MATEMATICA APLICADA
Descripción
Sumario:[EN] The discrete Cesaro (Banach) sequence spaces ces(r),1<r<infinity, have been thoroughly investigated for over 45 years. Not so for their dual spaces d(s) approximately equal to (ces(r))', which are somewhat unwieldy. Our aim is to undertake a further study of the spaces d(s) and of various operators acting between these spaces. It is shown that d(s)subset of d(t) whenever s <= t, with the inclusion being compact if s<t.The classical Cesaro operator C is continuous from d(s) into d(t) precisely when s <= t and compact precisely when s<t. Moreover, C even maps the larger space ces(s) continuously into d(s). This is a consequence of the Hardy-Littlewood maximal theorem and the remarkable property, for each 1<s<infinity, that x is an element of CN if and only if C(|x|)is an element of d(s). These results are used to analyze the spectrum and to determine the norm and the mean ergodicity of C acting in d(s). Similar properties for multiplier operators are also treated.