English

Solidity of type III Bernoulli crossed products

Operator Algebras 2016-08-24 v3 Dynamical Systems

Abstract

We generalize a theorem of Chifan and Ioana by proving that for any, possibly type III, amenable von Neumann algebra A0A_0, any faithful normal state φ0\varphi_0 and any discrete group Γ\Gamma, the associated Bernoulli crossed product von Neumann algebra M=(A0,φ0)ˉΓΓM=(A_0,\varphi_0)^{\mathbin{\bar{\otimes}}\Gamma}\rtimes \Gamma is solid relatively to L(Γ)\mathcal{L}(\Gamma). In particular, if L(Γ)\mathcal{L}(\Gamma) is solid then MM is solid and if Γ\Gamma is non-amenable and A0CA_0 \neq \mathbb{C} then MM is a full prime factor. This gives many new examples of solid or prime type III\mathrm{III} factors. Following Chifan and Ioana, we also obtain the first examples of solid non-amenable type III\mathrm{III} equivalence relations.

Keywords

Cite

@article{arxiv.1601.03666,
  title  = {Solidity of type III Bernoulli crossed products},
  author = {Amine Marrakchi},
  journal= {arXiv preprint arXiv:1601.03666},
  year   = {2016}
}

Comments

18 pages