Mathematics Colloquium

Invariant random subgroups (IRSs) are a probabilistic generalization of normal subgroups, and play an important role in the theory of probability measure preserving group actions. In this talk we will describe some newly discovered ways in which IRSs behave like normal subgroups. We will use these insights to show that some groups have very few IRSs.
 

Joint with Ian Biringer and Yair Hartman