Factoriality of twisted locally compact group von Neumann algebras (2412.15733v3)

Abstract: In this short note, we construct an exotic example of a locally compact group $G$ with a Borel $2$-cocycle $\omega$ such that the non-twisted group von Neumann algebra $L(G)$ is a factor, while the twisted group von Neumann algebra $L_\omega(G)$ has a diffuse center.