On spectral gap rigidity and Connes invariant χ(M)

2009/09/30 by Sorin Popa, Popa, Sorin
Mathematics · #Spectral Theory in Mathematical Physics #Advanced Differential Equations and Dynamical Systems #Holomorphic and Operator Theory

paper · doi:10.48550/arxiv.0909.5639

Abstract

We calculate Connes' invariant χ(M) for certain II₁ factors M that can be obtained as inductive limits of subfactors with spectral gap, then use this to answer a question he posed in 1975, on the structure of McDuff factors M with χ(M)=1.

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