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Haagerup and Størmer's conjecture on pointwise inner automorphisms

Published online by Cambridge University Press:  04 November 2024

Yusuke Isono*
Affiliation:
Research Institute for Mathematical Sciences (RIMS), Kyoto University, 606-8502 Kyoto, Japan [email protected]

Abstract

In 1988, Haagerup and Størmer conjectured that every pointwise inner automorphism of a type ${\rm III_1}$ factor is a composition of an inner and a modular automorphism. We study this conjecture and prove that every type ${\rm III_1}$ factor with trivial bicentralizer indeed satisfies this condition. In particular, this shows that Haagerup and Størmer's conjecture holds in full generality if Connes’ bicentralizer problem has an affirmative answer. Our proof is based on Popa's intertwining theory and Marrakchi's recent work on relative bicentralizers.

Type
Research Article
Copyright
© The Author(s), 2024. The publishing rights in this article are licensed to Foundation Compositio Mathematica under an exclusive licence

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