UNBOUNDED DERIVATIONS OF COMMUTATIVE CSTAR-ALGEBRAS

It is shown that an unbounded *-derivation δ of a unital commutative C*-algebra A is quasi well-behaved if and only if there is a dense open subset U of the spectrum of A such that, for any f in the domain of δ, δ(f) vanishes at any point of U where f attains its norm. An example is given to show th...

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Autor principal: Batty, C
Format: Journal article
Idioma:English
Publicat: Springer-Verlag 1978
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author Batty, C
author_facet Batty, C
author_sort Batty, C
collection OXFORD
description It is shown that an unbounded *-derivation δ of a unital commutative C*-algebra A is quasi well-behaved if and only if there is a dense open subset U of the spectrum of A such that, for any f in the domain of δ, δ(f) vanishes at any point of U where f attains its norm. An example is given to show that even if δ is closed it need not be quasi well-behaved. This answers negatively a question posed by Sakai for arbitrary C*-algebras. It is also shown that there are no-zero closed derivations on A if the spectrum of A contains a dense open totally disconnected subset. © 1978 Springer-Verlag.
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spelling oxford-uuid:53a7d03b-c721-4bd7-91c9-f8b33e808dd52022-03-26T16:33:10ZUNBOUNDED DERIVATIONS OF COMMUTATIVE CSTAR-ALGEBRASJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:53a7d03b-c721-4bd7-91c9-f8b33e808dd5EnglishSymplectic Elements at OxfordSpringer-Verlag1978Batty, CIt is shown that an unbounded *-derivation δ of a unital commutative C*-algebra A is quasi well-behaved if and only if there is a dense open subset U of the spectrum of A such that, for any f in the domain of δ, δ(f) vanishes at any point of U where f attains its norm. An example is given to show that even if δ is closed it need not be quasi well-behaved. This answers negatively a question posed by Sakai for arbitrary C*-algebras. It is also shown that there are no-zero closed derivations on A if the spectrum of A contains a dense open totally disconnected subset. © 1978 Springer-Verlag.
spellingShingle Batty, C
UNBOUNDED DERIVATIONS OF COMMUTATIVE CSTAR-ALGEBRAS
title UNBOUNDED DERIVATIONS OF COMMUTATIVE CSTAR-ALGEBRAS
title_full UNBOUNDED DERIVATIONS OF COMMUTATIVE CSTAR-ALGEBRAS
title_fullStr UNBOUNDED DERIVATIONS OF COMMUTATIVE CSTAR-ALGEBRAS
title_full_unstemmed UNBOUNDED DERIVATIONS OF COMMUTATIVE CSTAR-ALGEBRAS
title_short UNBOUNDED DERIVATIONS OF COMMUTATIVE CSTAR-ALGEBRAS
title_sort unbounded derivations of commutative cstar algebras
work_keys_str_mv AT battyc unboundedderivationsofcommutativecstaralgebras