[Binghamton Geometry/Topology Seminar] (no subject)

[Marco Varisco]

BINGHAMTON GEOMETRY/TOPOLOGY SEMINAR

Date: Thursday November 1, 2007

Time: 2:50 pm

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

Speaker: Yvonne Lai (University of California, Davis)

Title: An effective compactness theorem for Coxeter groups

Abstract: Through highly non-constructive methods, works by Bestvina,
Culler, Feighn, Morgan, Paulin, Rips, Shalen, and Thurston show that
if a finitely presented group does not split over a small subgroup,
then the space of its discrete and faithful actions on H^n, modulo
conjugation, is compact for all dimensions. We make this result
effective for Coxeter groups. We find that either the group splits
over a small subgroup or there is a constant C and a point in H^n that
is moved no more than C by any generator.