Geometry, Topology and Dynamics Seminar
Emily Stark
Tufts
Commensurability and quasi-isometric classification of hyperbolic surface group amalgams
Abstract: Two groups are abstractly commensurable if they contain isomorphic subgroups of finite index. Finitely generated groups that are abstractly commensurable are quasi-isometric, though the converse is false in general. Two questions in geometric group theory are to characterize the abstract commensurability and quasi-isometry classes within a class of groups, and to understand for which classes of groups the classifications coincide. I will present a solution within the class of groups isomorphic to the fundamental group of two closed hyperbolic surfaces identified along an essential simple closed curve in each.
Wednesday April 29, 2015 at 3:00 PM in SEO 636