Geometry and Topology Seminar 2019-2020
The Geometry and Topology seminar meets in room 901 of Van Vleck Hall on Fridays from 1:20pm - 2:10pm.
For more information, contact Tullia Dymarz.
Summer 2015
| date | speaker | title | host(s) |
|---|---|---|---|
| June 23 at 2pm in Van Vleck 901 | David Epstein (Warwick) | Splines and manifolds. | Hirsch |
Summer Abstracts
David Epstein (Warwick)
Splines and manifolds.
Fall 2015
| date | speaker | title | host(s) |
|---|---|---|---|
| September 4 | |||
| September 11 | [Hung Tran] (UW Milwaukee) | Relative divergence, subgroup distortion, and geodesic divergence | T. Dymarz |
| September 18 | |||
| September 25 | |||
| October 2 | |||
| October 9 | |||
| October 16 | Jacob Bernstein (Johns Hopkins University) | TBA | L. Wang |
| October 23 | Anton Izosimov (University of Toronto) | TBA | Mari-Beffa |
| October 30 | |||
| November 6 | |||
| November 13 | |||
| November 20 | |||
| Thanksgiving Recess | |||
| December 4 | |||
| December 11 | |||
Fall Abstracts
Hung Tran
Relative divergence, subgroup distortion, and geodesic divergence
In my presentation, I introduce three new invariants for pairs $(G;H)$ consisting of a finitely generated group $G$ and a subgroup $H$. The first invariant is the upper relative divergence which generalizes Gersten's notion of divergence. The second invariant is the lower relative divergence which generalizes a definition of Cooper-Mihalik. The third invariant is the lower subgroup distortion which parallels the standard notion of subgroup distortion. We examine the relative divergence (both upper and lower) of a group with respect to a normal subgroup or a cyclic subgroup. We also explore relative divergence of $CAT(0)$ groups and relatively hyperbolic groups with respect to various subgroups to better understand geometric properties of these groups. We answer the question of Behrstock and Dru\c{t}u about the existence of Morse geodesics in $CAT(0)$ spaces with divergence function strictly greater than $r^n$ and strictly less than $r^{n+1}$, where $n$ is an integer greater than $1$. More precisely, we show that for each real number $s>2$, there is a $CAT(0)$ space $X$ with a proper and cocompact action of some finitely generated group such that $X$ contains a Morse bi-infinite geodesic with the divergence equivalent to $r^s$.
Anton Izosimov
TBA
Jacob Bernstein
TBA
Archive of past Geometry seminars
2014-2015: Geometry_and_Topology_Seminar_2014-2015
2013-2014: Geometry_and_Topology_Seminar_2013-2014
2012-2013: Geometry_and_Topology_Seminar_2012-2013
2011-2012: Geometry_and_Topology_Seminar_2011-2012
2010: Fall-2010-Geometry-Topology