English

Hypertrace and entropy gap characterizations of property (T) for $\mathrm{II}_1$ factors

Operator Algebras 2024-06-10 v3 Dynamical Systems Group Theory

Abstract

We establish a hypertrace characterization of property (T) for II1\mathrm{II}_1 factors: Given a II1\mathrm{II}_1 factors MM, MM does not have property (T) if and only if there exists a von Neumann algebra A\mathcal{A} with MAM\subset \mathcal{A} such that A\mathcal{A} admits a MM-hypertrace but no normal hypertrace. For MM without property (T), such an inclusion MAM\subset \mathcal{A} also admits almost vanishing Furstenberg entropy. With the same construction of MAM\subset \mathcal{A}, we also establish similar characterizations of Haagerup property for II1\mathrm{II}_1 factors.

Keywords

Cite

@article{arxiv.2312.15110,
  title  = {Hypertrace and entropy gap characterizations of property (T) for $\mathrm{II}_1$ factors},
  author = {Shuoxing Zhou},
  journal= {arXiv preprint arXiv:2312.15110},
  year   = {2024}
}

Comments

Final version, to appear in Journal of Functional Analysis