A von Neumann algebra characterization of property (T) for groupoids

Abstract

For an arbitrary discrete probability-measure-preserving groupoid G, we provide a characterization of property (T) for G in terms of the groupoid von Neumann algebra L(G). More generally, we obtain a characterization of relative property (T) for a subgroupoid H⊂G in terms of the inclusion L(H)⊂L(G).

Files

Additional details