[Binghamton Geometry/Topology Seminar] (no subject)

[Ross Geoghegan]

                   BINGHAMTON GEOMETRY/TOPOLOGY SEMINAR


   NOTE: Through a glitch in our computer upgrade, an old announcement
   got resent this afternoon.  The correct current announcement follows:

   Date:  Thursday April 21, 2005

   Time:  2.50 pm

   Place: Library North 2205 followed by coffee/tea in the Anderson
          Reading Room.

   Speaker: Ben Schmidt (University of Michigan)

   Title:  Weakly hyperbolic group actions

Abstract: 
A group action on a closed Riemannian manifold is said to be weakly
hyperbolic provided that a finite family of group elements act by
partially hyperbolic diffeomorphisms with stable distributions jointly
spanning the tangent bundle. Weakly hyperbolic integer actions are
generated by an Anosov diffeomorphism, providing motivation for our
two main results: 1) ergodicity of volume preserving weakly hyperbolic
actions, and 2) weak hyperbolicity is inherited by the induced action on
the fundamental group for volume preserving weakly hyperbolic actions
(with a fixed point) of Kazhdan property (T) groups on tori. This work
stems from Zimmer's program of classifying the volume preserving ergodic
actions of lattices in higher rank Lie groups.


NOTE:  The seminar has a webpage where the semester's program is listed:

http://math.binghamton.edu/MATH/dept/topsem/index.html

It can also be linked from the Department's Home Page.
_____________________
IF YOU WANT TO BE REMOVED FROM THIS EMAIL LIST WRITE
ross at math.binghamton.edu