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Department of Mathematics,
University of California San Diego

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Math 211B - Group Actions Seminar

Homin Lee

Northwestern University

Higher rank lattice actions with positive entropy

Abstract:

We discuss about smooth actions on manifold by higher rank lattices. We mainly focus on lattices in $\mathrm{SL}_n(\mathbb{R})$ ($n$ is at least $3$). Recently, Brown-Fisher-Hurtado and Brown-Rodriguez Hertz-Wang showed that if the manifold has dimension at most $(n-1)$, the action is either isometric or projective. Both cases, we don't have chaotic dynamics from the action (zero entropy). We focus on the case when one element of the action acts with positive topological entropy. These dynamical properties (positive entropy element) significantly constrains the action. Especially, we deduce that if there is a smooth action with positive entropy element on a closed $n$-manifold by a lattice in $\mathrm{SL}_n(\mathbb{R})$ ($n$ is at least $3$) then the lattice should be commensurable with $\mathrm{SL}_n(\mathbb{Z})$. This is the work in progress with Aaron Brown.

Host: Brandon Seward

February 23, 2023

10:00 AM

AP&M 7218 and Zoom ID 967 4109 3409
Email an organizer for the password

 

Research Areas

Ergodic Theory and Dynamical Systems

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