Mathematics – Differential Geometry
Scientific paper
2002-03-11
Mathematics
Differential Geometry
Scientific paper
We observe that any regular Lie groupoid G over an manifold M fits into an extension $K \to G \to E$ of a foliation groupoid E by a bundle of connected Lie groups K. If $\FF$ is the foliation on M given by the orbits of E and T is a complete transversal to $\FF$, this extension restricts to T, as an extension $K_{T}\to G_{T}\to E_{T}$ of an \'etale groupoid $E_{T}$ by a bundle of connected groups $K_{T}$. We break up the classification into two parts. On the one hand, we classify the latter extensions of \'etale groupoids by (non-abelian) cohomology classes in a new \v{C}ech cohomology of \'{e}tale groupoids. On the other hand, given K and E and an extension $K_{T}\to G_{T}\to E_{T}$ over T, we present a cohomological obstruction to the problem of whether this is the restriction of an extension $K \to G \to E$ over M; if this obstruction vanishes, all extensions $K \to G \to E$ over M which restrict to a given extension over the transversal together form a principal bundle over a ``group'' of bitorsors under K.
No associations
LandOfFree
On the Classification of Regular Groupoids does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with On the Classification of Regular Groupoids, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the Classification of Regular Groupoids will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-619760