Reflecting isomorphisms of C*-algebras down to groupoids

20.05.2026, 10:15  –  Room 1.22, House 9
Forschungsseminar: Gruppen und Operatoralgebren

Jonathan Taylor (University of Potsdam)

It's certainly not true that two étale groupoids with isomorphic C*-algebras are themselves isomorphic (this fails even for finite groups). If however the isomorphism is induced by an appropriate morphism of the underlying groupoids, the answer becomes affirmative. The core strategy of this proof involves showing that any such isomorphism of the C*-algebras arising in this way must induce isomorphisms of the isotropy fibres in the underlying groupoids. From there it is straightforward to show that the groupoids themselves must already be isomorphic. This project is joint work with Ralf Meyer and Sven Raum.