Search results for "C*-algebra"

showing 7 items of 67 documents

Unbounded derivations and *-automorphisms groups of Banach quasi *-algebras

2018

This paper is devoted to the study of unbounded derivations on Banach quasi *-algebras with a particular emphasis to the case when they are infinitesimal generators of one parameter automorphisms groups. Both of them, derivations and automorphisms are considered in a weak sense; i.e., with the use of a certain families of bounded sesquilinear forms. Conditions for a weak *-derivation to be the generator of a *-automorphisms group are given.

Unbounded derivationPure mathematicsAutomorphisms groups and their infinitesimal generatorsInfinitesimalBanach quasi *-algebra01 natural sciencesMathematics::Group Theory*-Automorphisms groups and their infinitesimal generatorSettore MAT/05 - Analisi Matematica0103 physical sciencesFOS: MathematicsAutomorphisms groups and their infinitesimal generators; Banach quasi; Integrability of derivation; Unbounded derivations; Automorphisms groups and their infinitesimal generators; Banach quasi; Integrability of derivation; Unbounded derivationsBanach quasi0101 mathematicsOperator Algebras (math.OA)MathematicsGroup (mathematics)Applied Mathematics010102 general mathematicsIntegrability of derivationMathematics - Operator AlgebrasAutomorphismUnbounded derivationsFunctional Analysis (math.FA)Mathematics - Functional AnalysisBounded function010307 mathematical physicsGenerator (mathematics)
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Quasi *-algebras and generalized inductive limits of C*-algebras

2011

inductive limitJordan algebraGeneral MathematicsSubalgebraCurrent algebraUniversal enveloping algebraFiltered algebraAlgebraC*-algebrasSettore MAT/05 - Analisi MatematicaQuasi *-algebraAlgebra representationDivision algebraCellular algebraMathematics
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Exponentiating derivations of quasi∗-algebras: possible approaches and applications

2005

The problem of exponentiating derivations of quasi∗-algebras is considered in view of applying it to the determination of the time evolution of a physical system. The particular case where observables constitute a properCQ∗-algebra is analyzed.

lcsh:MathematicsPhysical systemTime evolutionFOS: Physical sciencesObservableMathematical Physics (math-ph)lcsh:QA1-939quasi ∗-algebraCQ*-algebraMathematics (miscellaneous)Settore MAT/05 - Analisi MatematicaCalculusSettore MAT/07 - Fisica MatematicaMathematical PhysicsMathematicsInternational Journal of Mathematics and Mathematical Sciences
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A note on *-derivations of partial *-algebras

2012

A definition of *-derivation of partial *-algebra through a sufficient family of ips-forms is proposed.

partial *-algebras sesquilinear forms *-derivationSettore MAT/05 - Analisi Matematica
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Locally convex quasi *-algebras: basic aspects and commutative case

2010

quasi *-algebrasSettore MAT/05 - Analisi Matematica
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Quasi *-algebras arising from extensions of positive linear functionals

2010

In this paper we show how some known quasi *-algebras can also be obtained through the construction of slight extensions of nonclosable positive linear functionals defined on dense *-subalgebras Ao of given topological *-algebras. Moreover, we consider also, for each of the functionals we present, their absolutely convergent extensions and the GNS *-representations of the quasi *-algebras arising in the process of extension.

slight extensionsSettore MAT/05 - Analisi MatematicaQuasi *-algebra
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Extensions of representable linear functionals to unitized quasi *-algebras

2013

This paper starts from noting that, under certain conditions, *-representability and extensibility to the unitized *-algebra of a positive linear functional, defined on a *-algebra without unit, are equivalent. Here some conditions for the equivalence of the same concepts for a hermitian linear functional defined on a quasi *-algebra $(\A,\Ao)$ without unit are given. The approach is twofold: on the one hand, conditions for the equivalence are exhibited by introducing a condition for the *- representability of the extension of a *-representable functional to the unitized quasi *-algebra, on the other hand a *-representable extension to the unitization of a hermitian linear functional by mea…

unitized quasi *-algebras.Settore MAT/05 - Analisi Matematica*-representable linear functional
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