In a sequence of celebrated works, Ratner classified invariant ergodic measures and orbit closures of actions of groups generated by unipotent elements on a homogenegous space. Namely, such an orbit closure must be a single orbit by a closed subgroup, and the invariant ergodic measure is the Haar measure on that orbit. In this talk, we go over a special case of Ratner's measure classification theorem when the action group is semisimple. We will follow the exhibition given by Einsiedler.
Zoom Info:
https://umich.zoom.us/j/91734725787 Speaker(s): Thang Nguyen (U Michigan)