Work

Every locally compact group is the outer automorphism group of a II1 factor

Year: 2025
Type: article
Abstract: We prove that every locally compact second countable group G arises as the outer automorphism group $\operatorname{Out} M$ of a II1 factor, which was so far only known for totally disconnected groups, compact groups, and a few isolated examples. We obtain this result by proving that every locally compact second countable group is a centralizer group, a class of Polish groups that arise naturally in ergodic theory and that may all be realized as $\operatorname{Out} M$ .
Author: Stefaan Vaes
Institution: KU Leuven
Language: English
Open Access status: green
OpenAlex ID: W4408945991
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Cites: 9
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Related to: 10