The classification problem for von Neumann factors

Publikation: Bidrag til tidsskriftTidsskriftartikelfagfællebedømt

We prove that it is not possible to classify separable von Neumann factors of types II, II or III, 0 ≤ λ ≤ 1, up to isomorphism by a Borel measurable assignment of "countable structures" as invariants. In particular the isomorphism relation of type II factors is not smooth. We also prove that the isomorphism relation for von Neumann II factors is analytic, but is not Borel.
OriginalsprogEngelsk
TidsskriftJournal of Functional Analysis
Vol/bind256
Udgave nummer8
Sider (fra-til)2710-2724
Antal sider15
ISSN0022-1236
DOI
StatusUdgivet - 15 apr. 2009

ID: 61337579