Groepoïden met een maat en von Neumannalgebra's

One of the goals of this project is to prove classification results for regular subalgebras of type III factors in terms of the associated groupoid. This naturally leads to questions of vanishing and approximate vanishing of cohomology for outer actions of amenable groups on type III factors. We also study outer automorphism groups of factors of type III and the factoriality problem for von Neumann algebras arising from measured groupoids.