English

W$^*$-superrigidity for coinduced actions

Operator Algebras 2018-05-30 v2 Dynamical Systems Functional Analysis

Abstract

We prove W^*-superrigidity for a large class of coinduced actions. We prove that if Σ\Sigma is an amenable almost-malnormal subgroup of an infinite conjugagy class (icc) property (T) countable group Γ\Gamma, the coinduced action ΓX\Gamma\curvearrowright X from an arbitrary probability measure preserving action ΣX0\Sigma\curvearrowright X_0 is W^*-superrigid. We also prove a similar statement if Γ\Gamma is an icc non-amenable group which is measure equivalent to a product of two infinite groups. In particular, we obtain that any Bernoulli action of such a group Γ\Gamma is W^*-superrigid.

Keywords

Cite

@article{arxiv.1711.04943,
  title  = {W$^*$-superrigidity for coinduced actions},
  author = {Daniel Drimbe},
  journal= {arXiv preprint arXiv:1711.04943},
  year   = {2018}
}
R2 v1 2026-06-22T22:45:07.271Z