On the connection theory of transitive Lie groupoids
arXiv:math/0307282
Abstract
Due to a result by Mackenzie, extensions of transitive Lie groupoids are equivalent to certain Lie groupoids which admit an action of a Lie group. This paper is a treatment of the equivariant connection theory and holonomy of such groupoids, and shows that such connections give rise to the transition data necessary for the classification of their respective Lie algebroids.
New version. Added results and new title. To appear in J. Diff. Geom. & Appl