Classification of \(SL(n,\mathbb R)\)-actions on closed
manifolds
October 27, 2025
1:00 pm 648 PGH
Abstract
Recently, Fisher and Melnick classified \(SL(n,\mathbb R)\)-actions on
\(n\)-dimensional manifolds for \(n \ge 3\). In this talk, we
generalize this result by classifying smooth or real-analytic
\(SL(n,\mathbb R)\)-actions on \(m\)-dimensional manifolds for \(3 \le
n \le m \le 2n-3\). This work is motivated by the Zimmer program and
is central to it, as Lie group actions restrict to their lattice
actions.
This classification relies on the linearization of \(SL(n, \mathbb
R)\)-actions when there is a global fixed point. The analytic case was
proved by Guillemin-Sternberg and Kushinirenko. We discuss the smooth
case which is ongoing joint work with Insung Park.