On amenable subalgebras of the group von Neumann algebra

In a joint work with Yair Hartman and Hanna Oppelmayer, we study the sub-von Neumann Algebras of the group von Neumann algebra $L\Gamma$. We will first show that $L\Gamma$ admits a maximal invariant amenable subalgebra. We will also introduce the notion of invariant probability measures on the space of sub-von Neumann algebras (IRAs) which is analogous to the concept of Invariant Random Subgroups. We shall show that amenable IRAs are supported on the maximal amenable invariant subalgebra.