Equality-case isomorphism classification

Prove that every bounded self-adjoint tuple with Lipschitz conjugate variables satisfying CD(c,∞) and saturating the free Poincaré bound C_P(X)=1/c generates a von Neumann algebra isomorphic to L(F₂).

Background

The paper proves an equality-case splitting theorem: saturation of the free Poincaré inequality produces a semicircular factor, and it identifies the generated algebra completely when at most one variable remains outside that factor. It then conjectures that the whole algebra must nevertheless be isomorphic to L(F₂) in every equality case, regardless of the dimension of the first eigenspace.

References

We are led to suggest the following conjecture.

— Convexity, the spectrum of free Laplacians and geometric consequences: a free KLS bound  (2610.22109 - Diez, 15 Oct 2026) in Conjecture labeled \ref{conj:obata-isomorphism}, Section 3, subsection “The curvature criterion and a strengthened free Obata theorem”