A systematic approach for invariants of C*-algebras

Abstract

We define a categorical framework in which we build a systematic construction that provides generic invariants for C*-algebras. The benefit is significant as we show that any invariant arising this way automatically enjoys nice properties such as continuity, metric on morphisms and a theory of ideals and quotients which naturally encapsulates compatibility diagrams. Consequently, any of these invariants appear as good candidates for the classification of non-simple C*-algebras. Further, it is worth mentioning that most of the existing invariants could be rewritten via this method. As an application, we define an Hausdorffized version of the unitary Cuntz semigroup and explore its potential towards classification results. We pose several open lines of research.