61 citations · 80 across the 8 of their papers we have counts for
7 papers · 1 filter
Graph morphisms as groupoid actors
Gilles G. de Castro, Ralf Meyer
We describe proper actors from the underlying groupoid of a graph C*-algebra to another étale groupoid in terms of bisections. This allows to understand graph morphisms and the *-h…
Bicategories of C*-correspondences as Dwyer-Kan localisations
Ralf Meyer
We show that the bicategory of proper correspondences is the Dwyer-Kan localisation of the category of C*-algebras at a certain class of *-homomorphisms.
Groupoid models for relative Cuntz-Pimsner algebras of groupoid correspondences
Ralf Meyer
A groupoid correspondence on an etale, locally compact groupoid induces a C*-correspondence on its groupoid C*-algebra. We show that the Cuntz-Pimsner algebra for this C*-correspon…
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…
A universal coefficient theorem for actions of finite groups on C*-algebras
Ralf Meyer, George Nadareishvili
The equivariant bootstrap class in the Kasparov category of actions of a finite group G consists of those actions that are equivalent to one on a Type I C*-algebra. Using a result…
Correspondences between graph C*-algebras
Rasmus Bentmann, Ralf Meyer
We describe proper correspondences from graph C*-algebras to arbitrary C*-algebras by K-theoretic data. If the target C*-algebra is a graph C*-algebra as well, we may lift an isomo…
Quantum group-twisted tensor products of C*-algebras II
Ralf Meyer, Sutanu Roy, Stanisław Lech Woronowicz
For a quasitriangular C*-quantum group, we enrich the twisted tensor product constructed in the first part of this series to a monoidal structure on the category of its continuous…