2025

Dec 16 (Tue) 11 am - 12 pm

KIAS (Room 1423) & Zoom https://kimsh.kr/vz

Sunhyuk Lim (SKKU)

Title: TBA

Abstract: TBA

Dec 22 (Mon) 10:30 am - 12 pm

KIAS (Room 1423) & Zoom https://kimsh.kr/vz

Dongryul M. Kim (Yale)

Title: Measure classification via geometric group theory

Abstract: In this talk, I will present my joint work with Inhyeok Choi that develops geometric group theoretic approaches to classifying invariant Radon measures on various dynamical systems arising from Teichmüller dynamics and homogeneous dynamics.

First, given a non-elementary subgroup of the mapping class group of a hyperbolic surface, we construct an invariant Radon measure on the space of measured laminations and prove that any ergodic invariant Radon measure on the recurrent measured laminations coincides with this measure. When the subgroup is the full mapping class group, this measure is the Thurston measure, and in this case the uniqueness on recurrent measured laminations was independently proved by Lindenstrauss--Mirzakhani and Hamenstädt.

Next, we classify all horospherical-invariant Radon measures on higher-rank Anosov and relatively Anosov homogeneous spaces. Our approaches towards both Teichmüller and homogeneous settings are based on geometric properties of certain geodesics, which we call squeezing.

2026