Families of hyperfinite subfactors with the same standard invariant and prescribed fundamental group

Arnaud Brothier; Stefaan Vaes

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arXiv · 1309.5354

Families of hyperfinite subfactors with the same standard invariant and prescribed fundamental group

Arnaud Brothier·Stefaan Vaes

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Abstract

We construct irreducible hyperfinite subfactors of index 6 with a prescribed fundamental group from a large family containing all countable and many uncountable subgroups of R_+. We also prove that there are unclassifiably many irreducible hyperfinite group-type subfactors of index 6 that all have the same standard invariant. More precisely, we associate such a subfactor to every ergodic measure preserving automorphism of the interval [0,1] and prove that the resulting subfactors are isomorphic if and only if the automorphisms are conjugate.

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Arnaud Brothier, Stefaan Vaes. 2013-09-20. Families of hyperfinite subfactors with the same standard invariant and prescribed fundamental group. https://arxiv.org/abs/1309.5354

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