Videos

Recent Progress in Topological and Geometric Structures in Low Dimensions: Rotation sets via the fine curve graph

Presenter
March 27, 2026
Keywords:
  • Surfaces
  • geometric 3-manifolds
  • mapping class groups
  • foliations
  • fibrations
  • Anosov flows
  • Teichmuller space
  • conformal structures
MSC:
  • 57M50 - General geometric structures on low-dimensional manifolds
Abstract
The fine curve graph is a variant of the curve graph for the homeomorphism group: a Gromov hyperbolic graph on which the homeomorphism group acts. In this talk we present joint work with Frédéric Le Roux linking the shape of the rotation set of a torus homeomorphism (a classical, dynamical conjugacy invariant) to the geometry of its action on the fine curve graph. As a consequence, one can construct homeomorphisms with positive scl close to the identity, and obtain Tits alternatives for (certain) subgroups of the homeomorphism group of the torus.