Our seminar meets Tuesdays at 4:30 in JCC 502. Talks are in person and also streamed on Zoom. You can subscribe to the GGTT mailing list at https://elist.tufts.edu/sympa/info/ggtt for details and announcements. The seminar organizers are Kim Ruane, Lorenzo Ruffoni and Genevieve Walsh.

DateNameTitle
Jan 24Lorenzo Ruffoni (Tufts)Hyperbolization, cubulation, and applications
Abstract:  Gromov introduced some “hyperbolization” procedures that turn a given polyhedron into a space of non-positive curvature. Charney and Davis developed a refined “strict hyperbolization” procedure that outputs a space of strictly negative curvature, and Ontaneda provided a Riemannian version that works in the smooth setting. These procedures have been used to construct examples of manifolds and groups that exhibit various pathologies, despite having negative curvature. In joint work with J. Lafont, we construct actions of the fundamental groups of these spaces on CAT(0) cube complexes. As an application, we obtain that these groups are virtually special, hence linear over the integers and residually finite. In particular, we obtain new examples of negatively curved Riemannian manifolds whose fundamental groups virtually algebraically fiber.
Jan 31no seminar
Feb 07Chandrika Sadanand (Bowdoin)Hyperbolic cone surfaces and polygonal billiards
Abstract: Consider a polygon-shaped billiard table in the hyperbolic plane on which a ball can roll along geodesics and reflect off of edges infinitely. In joint work with Viveka Erlandsson and Chris Leininger, we have characterized the relationship between the shape of the polygon and the set of possible sequences of edges visited consecutively by billiard balls rolling and reflecting around the polygon. In order to do this, we made an arguably more interesting characterization: when a hyperbolic metric with cone points on a surface is determined by the geodesics that do not pass through cone points. In this talk, we will explore these characterizations and the tools used to prove them.
Feb 14
Feb 21
Mar 02 (Thursday)Michael Hull (UNC Greensboro)TBA
Abstract:  TBA
Mar 07Tina Torkaman (Harvard)TBA
Abstract: TBA
Mar 14Carolyn Abbott (Brandeis)TBA
Abstract: TBA
Mar 21no seminar
Mar 28
Apr 04
Apr 11Alex Suciu (Northeastern)TBA
Abstract: TBA
Apr 18
Apr 25