A Galois Type Theorem in von Neumann Algebras

Hisashi Choda
1992 Proceedings of the American Mathematical Society  
We shall give a simple proof for a Galois type theorem: Let a be a dual free action of a discrete group G on a factor M . If an automorphism 9 of M leaves the fixed point algebra Ma pointwise invariant then there exists a go € G with 0 = ag0 .
doi:10.2307/2159261 fatcat:ifdxvztdhrck5fziq6f4ftzyxm