Hyperbolic Lunch

Hyperbolic lunch is an informal talk that takes place at noon in my office (BA 6188). They generally last around 90 minutes and the talks are often interrupted by many questions. People bring their lunches to my office and eat as they listen to the talk. The audience consists of graduate students and postdocs and an occasional faculty or undergraduate interested in hyperbolic geometry or related topics in geometry, topology, group theory and dynamics. The topics are often what someone has learned recently and not necessarily a result by the speaker.


If you are in Toronto and have a fun topic you can talk about, you should consider doing one of these lunches. The talks should be accessible to graduate students. We appreciate beautiful math even when it is elementary and would like to know about math as much as about stories of how math gets done.

2018 Schedule

Date Speaker Title
July 4 Jordan Hofmann Hyperbolic Isometries and the Double cover SU(2) to SO(3) (see notes)
June 14 Ivan Telpukhovskiy Arithmetic hyperbolic surfaces: without cusps
June 7 Ivan Telpukhovskiy Arithmetic hyperbolic surfaces: with cusps
May 17 Ruth Charney Artin groups: what are they and why are they interesting?
May 30 Adriano Pacifico Thurston Stretch Paths
May 10 Maxime Fortier Bourque Local maxima of the systole function
May 3 Ivan Telpukhovskiy Masur's criterion does not hold in Thurston metric
April 4 Yvon Verberne Strong Contractibility in the Mapping class group.
March 28 Bram Petri Random surfaces
March 22 Giulio Tiozzo Generating functions and counting in RAAGs
March 15 Assaf Bar-Natan How we tried to fix redistricting, and ended up doing group theory
March 7 Dmitri Gekhtman Dynamics in the space of bounded holomorphic functions on the polydisk
March 1 Jeffrey Carlson Commensurability of surface automorphisms
February 15 Justin Martel Kantorovich Singularity Functor and Homotopy-Reductions
February 8 Maxime Fortier Bourque The Art Gallery Problem
February 1 Yulan Qing Guirardel core and relative twisting
January 25 Keivan Mallahi Oppenheim conjecture, and its generalization to the S-arithmetic case
January 18 Tanran Zhang Hyperbolic-type distance on punctured spheres

2017 Schedule

Date Speaker Title
December 13 Funda Gültepe Cannon-Thurston map
December 8 Maxime Scott Teichmüller theorems for topological branched covers
November 15 Camille Hornez Automorphisms of hyperbolic groups and growth
October 31 Maxime Fortier Bourque Scissors congruences and Dehn's dissection theorem
October 25 Jeff Carlson Accidental Isomorphisms between Lie groups
October 11 Joseph Maher Generic foliations via electrification
October 4 Yulan Qing Efficient geodesic in the curve complex
September 27 Giulio Tiozzo Dimension of invariant subsets of the circle
September 20 Pat Hooper Maximal square tiled surface with regular cylinder patterns
September 8 Howard Masur Ergodic theory and interval exchange transformations
August 8 Yulan Qing Convexity of the Outer Space
August 1 Eko Hironaka The minimum dilatation for pseudo-Anosov mapping classes
July 26 Adriano Pacifico Maximal stretch over simple closed curves
July 19 Kasra Rafi Limit sets of Teichüller geodesics in PML
July 12 Anja Randecker Siegel-Veech constants and the diameter of translation surfaces
June 28 Jeff Carlson Reading Course III
June 21 Anne Thomas QI classification of Coxeter groups and Bowditch JSJ decomposition
June 7, 14 Aaron Fenyes Reading Course II
May 24, 30 Ivan Telpukhovskiy Reading Course I
May 3 Vitali Kapovitch Which subsets of R^n are CAT(0)
April 12 Ivan Telpukhovskiy The Euler characteristic of the moduli space of curves
April 5 Kasra Rafi A gentle introduction to the Teichmüller space of a torus
March 29 Anja Randecker Veech groups of Loch Ness monsters
March 14 Sam Taylor
March 8 Jonah Gaster
March 1 Aaron Fenyes Shearing Coordinates
February 8 Maxime Fortier Bourque How to compute Teichmüller distance numerically in the space of hexagons
January 18 Curt McMullen
January 11 Yvon Verberne How to Generate the Mapping Class Group