Title: Geometric finiteness in mapping class groups: examples and perspectives
Abstract: Going beyond the setting of convex cocompactness, there is an effort to develop a theory of geometric finiteness for subgroups of mapping class groups that captures a broader range of behaviors and relates these to the structure of Teichmuller space, the action on the curve complex and the geometry of surface group extensions. This talk will explain some of the motivation and goals of the theory and introduce recent examples and constructions. These examples include lattice Veech subgroups, which are perhapd the most compelling examples for geometric finiteness, as well as certain right-angled Artin group constructions and of combinations of reducible subgroups. This includes joint work with Matthew G. Durham, Christopher J. Leininger, and Alessandro Sisto and well as with Tarik Aougab, Harry Bray, Hannah Hoganson, Sara Maloni, and Brandis Whitfield.
Spring 2025
Feb 10 Spendcer Dowdall Geometric finiteness in mapping class groups: examples and perspectives
March 3 Xiangdong Xie
March 10 Tarik Aougab
April 28 Behrang Forghani
Fall 2024
August 23, Friday Sagnik Jana Sublinearly Morse boundary
September 9 Rachel Skipper Braiding groups of homeomorphisms of the Cantor set
October 21 Meenakshy Jyothis Towards Ivanov’s meta-conjecture for geodesic currents
November 4 Alex Margolis Coarse homological invariants of metric spaces
November 11 Petr Kosenko Random walks on Fuchsian groups and Hardy spaces: an unexpected connection
November 25 Ekaterina Rybak Frattini subgroups of hyperbolic-like groups
December 2 Dimitrios Nikolakopoulos Log-Concavity of Characteristic Polynomial Coefficients in Representable Matroids
Spring 2024
Feb 26 Thomas Ng Quotients of free products
March 4 Mark Pengitore Residual finiteness growth functions of surface groups with respect to characteristic quotients
March 18 Sahana Balasubramanya The semi simple theory of acylindricity in higher rank
