Applied Categorical Structures

, Volume 14, Issue 2, pp 151–164 | Cite as

Bounded and Unitary Elements in Pro-C*-algebras

  • Rachid El Harti
  • Gábor LukácsEmail author


A pro-C*-algebra is a (projective) limit of C*-algebras in the category of topological *-algebras. From the perspective of non-commutative geometry, pro-C*-algebras can be seen as non-commutative k-spaces. An element of a pro-C*-algebra is bounded if there is a uniform bound for the norm of its images under any continuous *-homomorphism into a C*-algebra. The *-subalgebra consisting of the bounded elements turns out to be a C*-algebra. In this paper, we investigate pro-C*-algebras from a categorical point of view. We study the functor (−) b that assigns to a pro-C*-algebra the C*-algebra of its bounded elements, which is the dual of the Stone-Čech-compactification. We show that (−) b is a coreflector, and it preserves exact sequences. A generalization of the Gelfand duality for commutative unital pro-C*-algebras is also presented.

Key words

pro-C*-algebra Gelfand duality Stone-Čech-compactification Tychonoff space strongly functionally generated k-space kR-space bounded spectrally bounded coreflection exact 

Mathematics Subject Classification (2000)

18A05 46H05 46J05 46K05 


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© Springer Science + Business Media B.V. 2006

Authors and Affiliations

  1. 1.Department of MathematicsUniversity Hassan I, FST de SettatSettatMorocco
  2. 2.Department of Mathematics and StatisticsDalhousie UniversityHalifaxCanada

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