Generalised Gelfand Spectra of Nonabelian Unital C*-Algebras

Abstract

To each unital C*-algebra A we associate a presheaf Σ^A, called the spectral presheaf of A, which can be regarded as a generalised Gelfand spectrum. We develop a categorical notion of local duality and show that there is a contravariant functor from the category of unital C*-algebras to a suitable category of presheaves containing the spectral presheaves. We clarify how much algebraic information about a C*-algebra is contained in its spectral presheaf. A nonabelian unital C*-algebra A that is neither isomorphic to C^2 nor to B(C^2) is determined by its spectral presheaf up to quasi-Jordan isomorphisms. For a particular class of unital C*-algebras, including all von Neumann algebras with no type I_2 summand, the spectral presheaf determines the Jordan structure up to isomorphisms.

43 pages, no figures; v2: improved presentation, longer introduction and outlook section, additional references, minor corrections, all main results unchanged

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Cited by in corpus (5)

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• Topos quantum theory with short posets