Commuting-Square Subfactors and Central Sequences

Richard Burstein

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arXiv · 0808.2487

Commuting-Square Subfactors and Central Sequences

Richard Burstein

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Abstract

Let $M_0 \subset M_1$ be a finite-index infinite-depth hyperfinite $II_1$ subfactor and $ω$ a free ultrafilter of the natural numbers. We show that if this subfactor is constructed from a commuting square then the central sequence inclusion $M_0^ω \cap M_1' \subset (M_0)_ω$ has infinite Pimnser-Popa index. We will also demonstrate this result for certain infinite-depth hyperfinite subfactors coming from groups.

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Richard Burstein. 2008-08-19. Commuting-Square Subfactors and Central Sequences. https://arxiv.org/abs/0808.2487

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