Hebrew University Amitsur Algebra Seminar ---------------------------------- Time: Thursday, February 2, 12:00-13:15 Place: math 209 Speaker: Menny Aka (HUJI) Title: Arithmetic groups with isomorphic finite quotients Abstract: Two finitely generated groups have the same set of finite quotients if and only if their profinite completions are isomorphic. Consider the map which sends (the isomorphism class of) an S-arithmetic group to (the isomorphism class of) its profinite completion. We show that for a wide class of S-arithmetic groups, this map is finite to one, while the the fibers are of unbounded size. In the talk I will concentrate on giving interesting families of non-isomorphic arithmetic groups which are profinitely isomorphic and explain how they fit in the scheme of my proof. You are cordially invited! <http://math.huji.ac.il/amitsur.html> --------------------------------------------------------- Technion Math Net-2 (TECHMATH2) Editor: Michael Cwikel <techm@math.technion.ac.il> Announcement from: Gili Schul <gili.schul@mail.huji.ac.il>