Prof. Elon Lindenstrauss (Hebrew University of Jerusalem), Colloquium

Title:  Joining of higher rank homogenous actions

(j\w M. Einsidler)

Title:  Higher rank homogeneous actions display subtle rigidity properties that are not yet well understood. One situation where the state of knowledge seems to be quite satisfactory is regarding joinings of higher rank diagonalizable actions on quotients of semisimple groups.

This situation appears quite naturally in applications, and I will survey a few of these, including a result of Aka, Einsiedler and Shapira regarding the joint distribution of points on a sphere and the shape of its perpendicular lattice.