Achievement of continuity of $(ϕ,ψ)$-derivations without continuity

dc.creatorHejazian, S.
dc.creatorJanfada, A. R.
dc.creatorMirzavaziri, M.
dc.creatorMoslehian, M. S.
dc.date2006-11-01
dc.date2007-01-21
dc.date.accessioned2026-07-07T07:41:56Z
dc.date.available2026-07-07T07:41:56Z
dc.descriptionSuppose that $\calak$ is a $C^*$-algebra acting on a Hilbert space $\calhk$, and that $ϕ, ψ$ are mappings from $\calak$ into $B(\calhk)$ which are not assumed to be necessarily linear or continuous. A $(ϕ, ψ)$-derivation is a linear mapping $d: \calak \to B(\calhk)$ such that $$d(ab)=ϕ(a)d(b)+d(a)ψ(b)\quad (a,b\in \calak).$$ We prove that if $ϕ$ is a multiplicative (not necessarily linear) $*$-mapping, then every $*$-$(ϕ,ϕ)$-derivation is automatically continuous. Using this fact, we show that every $*$-$(ϕ,ψ)$-derivation $d$ from $\calak$ into $B(\calhk)$ is continuous if and only if the $*$-mappings $ϕ$ and $ψ$ are left and right $d$-continuous, respectively.
dc.descriptionTo appear in Bull. Belgian Math Soc
dc.identifierhttps://arxiv.org/abs/math/0611016
dc.identifierhttp://arxiv.org/abs/math/0611016
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/122300
dc.subjectFunctional Analysis
dc.subjectOperator Algebras
dc.subject46L57, 46L05, 47B47
dc.titleAchievement of continuity of $(ϕ,ψ)$-derivations without continuity
dc.typetext

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