Homological dimension of discrete subgroups in higher rank Lie groups

Prof. Shi Wang
2025-06-13 10:30-11:30
MCM210

Speaker: Prof. Shi Wang (ShanghaiTech University)
Time: 10:30-11:30  June 13, 2025 (Friday)
Venue: MCM210
Title: Homological dimension of discrete subgroups in higher rank Lie groups
Abstract: Given a discrete subgroup H in a higher rank non-compact simple real Lie group G. We show that either H is a lattice in G, or the homological dimension of H is bounded above by (n-1/8r), where n is the dimension of the symmetric space G/K and r is the real rank of G. The proof uses a geometric gradient flow motivated by the Patterson-Sullivan theory and the barycenter map of Besson-Courtois-Gallot. This is joint work with Chris Connell and Ben McReynolds.