4 papers
Twisted operator algebras of self-similar groupoid actions on arbitrary graphs
B. K. Kwaśniewski, A. Mundey
We study self-similar groupoid actions on arbitrary directed graphs together with -valued twists that exhaust the second cohomology group of the associated Zappa-Szép p…
Type semigroups for twisted groupoids and a dichotomy for groupoid C*-algebras
Bartosz K. Kwaśniewski, Ralf Meyer, Akshara Prasad
We develop a theory of type semigroups for arbitrary twisted, not necessarily Hausdorff étale groupoids. The type semigroup is a dynamical version of the Cuntz semigroup. We relate…
Banach algebras associated to twisted étale groupoids: simplicity and pure infiniteness
Krzysztof Bardadyn, Bartosz Kwaśniewski, Andrew McKee
We define reduced and essential Banach algebras associated to a twisted étale (not necessarily Hausdorff) groupoid and extend some fundamental results f…
Fourier--Stieltjes category for twisted groupoid actions
Alcides Buss, Bartosz Kwaśniewski, Andrew McKee +1
We extend the theory of Fourier--Stieltjes algebras to the category of twisted actions by étale groupoids on arbitrary C*-bundles, generalizing theories constructed previously by B…