Strongly Singular Masas in Type II₁ Factors

2001/07/10 by Sinclair, Allan, Smith, Roger
#46L05 #FOS: Mathematics #Operator Algebras (math.OA)

paper · doi:10.48550/arxiv.math/0107075

Abstract

In this paper we introduce and study strongly singular maximal abelian self-adjoint subalgebras of type II₁ factors. We show that certain elements of free groups and of non-elementary hyperbolic groups generate such masas, and these also give new examples of masas for which Popa's invariant delta is 1. We also explore the connection between Popa's invariant and strong singularity.

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