Junsheng Fang, Texas A&M University
Mixing subalgebras of finite von Neumann algebras

Jolissaint and Stalder introduced the defintion of weak mixing and mixing for subalgebras of finite von Neumann algebras. They proved that a measure prserving action of a countable group on a finite measure space is (weakly) mixing if and only if the von Neumann subalgebra induced by the group is (weakly) mixing in the cross-product finite von Neumann algebra. In this talk, I will give a characterization of weak mixing subalgebras in terms of "normalizers" of the subalgebras. I will also talk about some interesting properties of mixing subalgebras. This is joint work with Jan Cameron and Kunal Mukherjee.