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The Stacks project

History of tag 049A

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changed the statement 2013-05-24 719c185
LaTeX: \etale

Introduced the macro

\def\etale{{\acute{e}tale}}

and replaced all occurences of \acute{e}tale by \etale
changed the statement 2010-10-09 2b090dd
End conversion of etale to \'etale.
changed the statement 2010-07-01 f396b03
The stack of torsors

	There are many different possible definitions for the stack of
	torsors for a group algebraic space G over a base B. You can
	look at principal homogeneous spaces for the fpqc topology, or,
	and this is more natural for us, look at fppf G-torsors. One
	reason this is natural is that you get the same thing as looking
	at G-torsors where you think of G as a sheaf!

	If G is a group scheme over a scheme, then you could also just
	look at those fppf G-torsors which are representable. Of course
	this is somehow completely the wrong thing to do, but on the
	other hand it is what comes natural since we know more about
	schemes than about algebraic spaces.

	We try to discuss all the possible variants extensively in a
	section in the chapter "Examples of Stacks". In the future we
	will add some lemmas/propositions/theorems saying that if G has
	reasonable properties then these stacks all agree.
changed the statement 2010-06-02 4944f74
Lemmas on maps of groupoids on fields

	Images of such maps are often again groupoids, etc. Similar to
	lemmas on homomorphisms of group schsmes over fields.
assigned tag 049A 2010-03-01 bc8624b
More Morphisms Spaces: Finish proof characterization finite presentation

	Also add the chapter to the project, some fixes in scripts,
	added tags, etc
created statement with label definition-principal-homogeneous-space in groupoids.tex 2010-02-27 08e7da2
Groupoids: Section on torsors

	Mainly definitions