We show that for a countable exact group, having positive first ℓ 2-Betti number implies proper proximality in this sense of [3]. This is achieved by showing a cocycle superrigidity …
P Hiatt, J Peterson, S Popa - Journal of Functional Analysis, 2024 - Elsevier
We study several classes of Banach bimodules over a II 1 factor M, endowed with topologies that make them “smooth” with respect to L p-norms implemented by the trace τ on M. Thus …
M Caspers - Comptes Rendus. Mathématique, 2023 - comptes-rendus.academie-sciences …
Let Mq (HR) be the q-Gaussian von Neumann algebra associated with a separable infinite dimensional real Hilbert space HR where− 1< q< 1. We show that Mq (HR) ̸≃ M0 (HR) for …
In this paper, the notion of proper proximality (introduced by Boutonnet, Ioana, and Peterson [Ann. Sci. Éc. Norm. Supér.(4) 54 (2021), 445–482]) is studied and classified in various …
D Drimbe - Compositio Mathematica, 2023 - cambridge.org
We single out a large class of groups are 'rigid'. In particular, we provide an alternative solution to a question of Popa that was recently answered by Ding, Kunnawalkam Elayavalli …
C Ding, SK Elayavalli - Communications in Mathematical Physics, 2024 - Springer
Using computations in the bidual of B (L 2 M) we develop a new technique at the von Neumann algebra level to upgrade relative proper proximality to full proper proximality. This …
We introduce the notion of biexactness for general von Neumann algebras, naturally extending the notion from group theory. We show that biexactness implies solidity for von …
S Zhou - Journal of Functional Analysis, 2024 - Elsevier
We establish a hypertrace characterization of property (T) for II 1 factors: Given a II 1 factors M, M does not have property (T) if and only if there exists a von Neumann algebra A with …
T Berendschot, S Vaes - arXiv preprint arXiv:2212.11704, 2022 - arxiv.org
We give a simple and explicit proof that the free group $\mathbb {F} _2 $ admits a measure equivalence embedding into any nonamenable locally compact second countable (lcsc) …