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arXiv · 1206.4182

Openness of versality via coherent functors

Jack Hall
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Abstract

We give a proof of openness of versality using coherent functors. As an application, we streamline Artin's criterion for algebraicity of a stack. We also introduce multi-step obstruction theories, employing them to produce obstruction theories for the stack of coherent sheaves, the Quot functor, and spaces of maps in the presence of non-flatness.

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Jack Hall. 2013-04-08. Openness of versality via coherent functors. https://arxiv.org/abs/1206.4182

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