Strongly compact algebras

An algebra of bounded linear operators on a Hilbert space is said to be strongly compact if its unit ball is relatively compact in the strong operator topology. A bounded linear operator on a Hilbert space is said to be strongly compact if the algebra generated by the operator and the identity is st...

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Detalles Bibliográficos
Autores: Lacruz Martín, Miguel Benito, Lomonosov, Victor, Rodríguez Piazza, Luis
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2006
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/52346
Acceso en línea:http://hdl.handle.net/11441/52346
Access Level:acceso abierto
Palabra clave:Topological algebra
Linear operator
Hilbert space
Invariant subspace problem
Strongly compact algebra
Spectral representation
Descripción
Sumario:An algebra of bounded linear operators on a Hilbert space is said to be strongly compact if its unit ball is relatively compact in the strong operator topology. A bounded linear operator on a Hilbert space is said to be strongly compact if the algebra generated by the operator and the identity is strongly compact. This notion was introduced by Lomonosov as an approach to the invariant subspace problem for essentially normal operators. First of all, some basic properties of strongly compact algebras are established. Next, a characterization of strongly compact normal operators is provided in terms of their spectral representation, and some applications are given. Finally, necessary and sufficient conditions for a weighted shift to be strongly compact are obtained in terms of the sliding products of its weights, and further applications are derived.