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arXiv · math/0611349

Injective and projective Hilbert C*-modules, and C*-algebras of compact operators

Michael Frank·Vern I. Paulsen
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Abstract

We consider projectivity and injectivity of Hilbert C*-modules in the categories of Hilbert C*-(bi-)modules over a fixed C*-algebra of coefficients (and another fixed C*-algebra represented as bounded module operators) and bounded (bi-)module morphisms, either necessarily adjointable or arbitrary ones. As a consequence of these investigations, we obtain a set of equivalent conditions characterizing C*-subalgebras of C*-algebras of compact operators on Hilbert spaces in terms of general properties of Hilbert C*-modules over them. Our results complement results recently obtained by B. Magajna, J. Schweizer and M. Kusuda. In particular, all Hilbert C*-(bi-)modules over C*-algebras of compact operators on Hilbert spaces are both injective and projective in the categories we consider. For more general C*-algebras we obtain classes of injective and projective Hilbert C*-(bi-)modules.

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Michael Frank, Vern I. Paulsen. 2008-02-18. Injective and projective Hilbert C*-modules, and C*-algebras of compact operators. https://arxiv.org/abs/math/0611349

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