Geometry, Topology and Dynamics Seminar
Noah Caplinger
University of Chicago
Groups acting on horocyclic products
Abstract: Horocyclic products are a well-studied class of metric spaces that provide models for various solvable groups. Key examples include the universal cover of mapping tori of expanding maps or Anosov maps on Nilmanifolds. Horocyclic products have played a key role in many quasi-isometric rigidity results in the past few decades.
In this talk, I will give lots of examples of groups acting on horocyclic products and explain a theorem of mine and Daniel Levitin's which says that essentially all examples of finitely presented groups acting on horocyclic products come from expanding or Anosov maps.
Wednesday November 19, 2025 at 3:00 PM in 636 SEO