Stefan Wagner

activity

20242026

collaborators

6 papers

math.OA2026

Spectral geometry of saturated Fell bundles

Stefan Wagner

Let $B = (B_{g})_{g \in G}$ be a saturated Fell bundle over a countable discrete group, equipped with a spectral triple. We give explicit sufficient conditions for lifting this…

math.RA2026

Factor systems and geometric structures of strongly graded rings

Joakim Arnlind, Stefan Wagner

Graded rings provide a natural algebraic framework for encoding symmetry via decompositions into homogeneous components indexed by a group, together with multiplication rules refle…

math.OA2026

Weak Centrality of unital C(X)-algebras

Bharat Talwar, Prahlad Vaidyanathan, Stefan Wagner

This paper establishes a fibrewise characterization of weak centrality for unital $C (X)$ -algebras whose defining homomorphism maps $C (X)$ onto the center: such an algebra is weakly…

math.OA2025

Noncommutative principal bundles and central extensions

Stefan Wagner

Motivated by the classical theory of spin structures, we develop a theory for lifting free C $^{*}$ -dynamical systems, a.k.a. noncommutative principal bundles, along central extension…

math.OA2025

Saturated Fell bundles and their classification

Natã Machado, Stefan Wagner

We present a comprehensive classification theory for saturated Fell bundles over locally compact groups, utilizing data associated with their base group and unit fiber. This framew…

math.OA2024

Realizations of free actions via their fixed point algebras

Kay Schwieger, Stefan Wagner

Let $G$ be a compact group, let $B$ be a unital C $^{*}$ -algebra, and let $(A, G, α)$ be a free C $^{*}$ -dynamical system, in the sense of Ellwood, with fixed point alg…