The disjointness phenomena, defined by Hillel Furstenberg is his landmark 1967 paper, plays a profound role in modern ergodic theory. I will introduce the notion of joinnings and disjointness and give and prove basic properties. Afterwards, we will turn into studying questions regarding joinnings in homogeneous dynamics. In particular if time permits I will discuss a beautiful result of Venkatesh, effectivazing an argument of Bourgain, showing disjointness between flows on tori (and more generally - nilflows) and horocyclic flows (on compact quotients).

We will use https://umich.zoom.us/j/91734725787 - no password require (for now).
Speaker(s): Asaf Katz (U Michigan)