110
reads

Li-Huei Liu

2012-02-09
14:00:00 - 15:00:00

308 , Mathematics Research Center Building (ori. New Math. Bldg.)

If (M,g) is a Riemannian manifold and (x,y) belonging to M*M, then a set P\{x,y} is said to be a blocking set for (x,y) if every geodesic from x to y passes through a point of P. If no pair (x,y) in M*M has a finite blocking set, then (M,g) is said to be totally insecure. We prove that there exist real analytic metrics h on S^2 such that each (S^2,h) is totally insecure.