On invariant subalgebras of group $C^{\ast }$ and von Neumann algebras

Mehrdad Kalantar, Nikolaos Panagopoulos

Given an irreducible lattice $\Gamma$ in the product of higher rank simple Lie groups, we prove a co-finiteness result for the $\Gamma$-invariant von Neumann subalgebras of the group von Neu…