Talk:Lie groupoid

Assessment comment

The comment(s) below were originally left at Talk:Lie groupoid/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

Hi, here are two points which could be improved: the composition in the exemple of the groupoid associated to a principal bundle is not clear. There is no definition of a Morita morphism, but rather an example. best, Ilroth (talk) 08:21, 28 August 2009 (UTC)

Last edited at 08:21, 28 August 2009 (UTC). Substituted at 02:17, 5 May 2016 (UTC)

Examples Needed

This page should have explicit examples of Lie groupoids. Some examples should include

• Lie Groupoids from the Analytification of smooth groupoid schemes over $\mathbb {C}$
• Actions of $U(1)$ and discrete subgroups on $S^{n}$
• Quotient stacks from affine actions e.g. $\mathbb {Z} /2$ acting on $\mathbb {R} ^{2}$ by

${\begin{aligned}x\mapsto -x&y\mapsto -y\end{aligned}}$

• Lie groupoids from homogeneous spaces — Preceding unsigned comment added by 50.246.213.170 (talk) 00:46, 5 August 2017 (UTC)
• Another interesting example is the morphism of Lie-Groupoids induced by an action on a fiber bundle. — Preceding unsigned comment added by 128.138.65.181 (talk) 01:07, 20 August 2017 (UTC)

Further details needed

Some of the examples are incomplete, as they do not explain how the Lie Groupoid is actually obtained; most notably, it is not explained how a foliation gives a Lie Groupoid. --AlephMal (talk) 16:12, 10 January 2020 (UTC)