On II${}_1$ factors arising from 2-cocycles of w-rigid groups

Remus Nicoara, Sorin Popa, Roman Sasyk

We consider ${\text{II}}_1$ factors $L_{\mu }(G)$ arising from 2-cocyles $\mu \in {\text{H}}^2(G,\mathbb{T})$ on groups $G$ containing infinite normal subgroups $H\subset G$ with the rela…