# Reference for moduli stack of principal G-bundles?

Hi,

I'm looking for a reference for the fact that the moduli stack $M_{GL_r,X}$ of $GL_r$-bundles over $X$ is an algebraic (Artin) stack. I'm only interested in the case where $X$ is a curve (for now).

I think this is supposed to be in Laumon-Moret--Bailly's "Champs Algebriques", but my French is not so great and I have been unable to find it in there. If it is actually in there, can you help a non-Francophone out?

Thanks!

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See theorem 4.6.2.1 on page 29 of above. –  Donu Arapura Aug 4 '11 at 19:20

I actually don't think$^{\dagger}$ that this example is in Laumon/Moret-Bailey, but Jonathan Wang's senior thesis is a detailed write up in the style of LMB (and in English!) of this fact: http://math.harvard.edu/theses/senior/wang/wang.pdf.

$^{\dagger}$ Edit: I stand corrected!

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Thanks Moosbrugger, this is a really nice document. –  Kevin H. Lin Aug 5 '11 at 4:30