4 papers · 1 filter
Properly proximal countable measured groupoids
Adriana Fernández Quero, Kai Toyosawa
We introduce the notion of proper proximality for countable measured groupoids, extending the corresponding notion for countable groups. We prove that this groupoid property is equ…
Amenable absorption in von Neumann algebras of hyperbolic groups
Juan Felipe Ariza Mejia, Ionut Chifan, Adriana Fernandez Quero +1
We prove that the von Neumann algebra $\cL(G)$ associated with any hyperbolic group satisfies the following \emph{amenable absorption property}: for any infinite maximal amenab…
A class of II factors without non-trivial crossed product decompositions
Adriana Fernández Quero, Adrian Ioana, Hui Tan
We introduce a class of separable II factors admitting no non-trivial crossed product decompositions: , for any trace preserving action $G\curvearro…
Non-amenable C-superrigid groups that are not W-superrigid
Juan Felipe Ariza Mejía, Ionuţ Chifan, Adriana Fernández Quero
Using techniques at the intersection of deformation/rigidity theory, geometric group theory, and the theory of -algebras, we construct a continuum of nonamenable groups th…