Kadison–Kastler Stability and the Similarity Problem. The spatial 6 to distinguish the hyperfinite II1 factor from the free group factors).
Let Γ = F n = ⟨ a 1, a 2,..., a n | ⟩ the free group with n generator. It's ICC iff n ≥ 2. Free group factor isomorphism problem : L (F n) ≃ L (F.
Generator problem for von Neumann algebras: Are every von Free group factor isomorphism problem : L (F n) ≃ L (F m), ∀ n, m ≥ 2?.