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A Galois type theorem in von Neumann algebras

Author: Hisashi Choda
Journal: Proc. Amer. Math. Soc. 115 (1992), 415-417
MSC: Primary 46L55; Secondary 46L40
MathSciNet review: 1081090
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Abstract: We shall give a simple proof for a Galois type theorem: Let $ \alpha $ be a dual free action of a discrete group $ {\text{G}}$ on a factor $ M$. If an automorphism $ \theta $ of $ M$ leaves the fixed point algebra $ {M^\alpha }$ pointwise invariant then there exists a $ {g_0} \in G$ with $ \theta = {\alpha _{{g_0}}}$.

References [Enhancements On Off] (What's this?)

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Keywords: Galois theory, von Neumann algebra, factor, action, expectation
Article copyright: © Copyright 1992 American Mathematical Society

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