pith. sign in

arxiv: 1502.02391 · v2 · pith:CB53KSHAnew · submitted 2015-02-09 · 🧮 math.OA · math.DS· math.GR

OE and W* superrigidity results for actions by surface braid groups

classification 🧮 math.OA math.DSmath.GR
keywords groupssurfacebraidmeasureresultsactionergodicfree
0
0 comments X
read the original abstract

We show that several important normal subgroups $\Gamma$ of the mapping class group of a surface satisfy the following property: any free, ergodic, probability measure preserving action $\Gamma \curvearrowright X$ is stably OE-superrigid. These include the central quotients of most surface braid groups and most Torelli groups and Johnson kernels. In addition, we show that all these groups satisfy the measure equivalence rigidity and we describe all their lattice-embeddings. Using these results in combination with previous results from [CIK13] we deduce that any free, ergodic, probability measure preserving action of almost any surface braid group is stably W*-superrigid, i.e., it can be completely reconstructed from its von Neumann algebra.

This paper has not been read by Pith yet.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.