1.ETH Zürich, Rämistrasse 101, Zürich, 8092, Switzerland ;2.The Einstein Institute of Mathematics, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel ;
Abstract:
Publications mathématiques de l'IHÉS - We show that joinings of higher rank torus actions on $S$ -arithmetic quotients of semi-simple or perfect algebraic groups must be algebraic.