Working Groups
Reading Groupoid - Differentiable Stacks I: Equivalences of Lie Groupoids
Speaker: Óscar Carballal (UCM)Date: Tuesday, 13 October 2026 - 15:30-17:00Place: Aula Gris 3, ICMAT
Online: https://us02web.zoom.us/j/82328231233?pwd=nwEIkqmQcT6ls0tPaxubeAbTXXhTtY.1
Abstract:
This is the first in a series of lectures on differentiable stacks. We compare several notions of equivalence between Lie groupoids: isomorphisms, strong equivalences, and Morita maps. We then present a theorem of del Hoyo characterising Morita maps as those Lie groupoid morphisms that preserve transversal data, namely, those inducing a homeomorphism between orbit spaces and isomorphisms between the normal representations of the corresponding isotropy groups.
