3 papers
math.OA2026
Von Neumann algebras as reduced twisted groupoid -algebras
Alcides Buss, Luiz Felipe Garcia, Tomás Pacheco
We characterize the von Neumann algebras that are isomorphic, as -algebras, to reduced twisted -algebras of locally compact Hausdorff groupoids equipped with continuous H…
math.OA2026
B(H) is not a twisted groupoid C*-algebra
Alcides Buss, Luiz Felipe Garcia, Tomás Pacheco
We show that for an infinite dimensional Hilbert space cannot be realized as the reduced twisted -algebra of any locally compact Hausdorff étale groupoid. The proof…
math.OA2025
On weakly amenable groupoids
Tomás Pacheco
In this work, we study groupoids and their approximation properties, generalizing both the definitions and some known results for the group case. More precisely, we introduce weak…