The Weizmann Institute of Science Faculty of Mathematics and Computer Science Seminar in Geometry and Topology Seminar Room, Room 261, Ziskind Building on Sunday, December 26, 2010 at 14:00 Note unusual day and time Eugene Gutkin University of Torun will speak on Security and flatness Abstract: A manifold is secure if the geodesics between any pair of points can be blocked by a finite set of point obstacles. Conjecture: a compact manifold is secure iff it is flat. I will report on a proof of this for surfaces. --------------------------------------------------------- Technion Math Net-2 (TECHMATH2) Editor: Michael Cwikel <techm@math.technion.ac.il> Announcement from: Diana Mandelik <diana.mandelik@weizmann.ac.il>