Measured quantum groupoids with a central basis
arXiv:0808.4052
Abstract
Mimicking the von Neumann version of Kustermans and Vaes' locally compact quantum groups, Franck Lesieur had introduced a notion of measured quantum groupoid, in the setting of von Neumann algebras. In this article, we suppose that the basis of the measured quantum groupoid is central; in that case, we prove that a specific sub- algebra is invariant under all the data of the measured quantum groupoid; moreover, this sub--algebra is a continuous field of -algebras; when the basis is central in both the measured quantum groupoid and its dual, we get that the measured quantum groupoid is a continuous field of locally compact quantum groups. On the other hand, using this sub--algebra, we prove that any abelian measured quantum groupoid comes from a locally compact groupoid.
to be published in Journal of Operator Theory