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arXiv · 2101.02450

Fixed point stacks under groups of multiplicative type

Matthieu Romagny
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Abstract

We prove that if a group scheme of multiplicative type acts on an algebraic stack with affine, finitely presented diagonal then the stack of fixed points is algebraic. For this, we extend two theorems of [SGA3.2] on functors of subgroups of multiplicative type, and functors of homomorphisms from a group of multiplicative type.

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Matthieu Romagny. 2021-01-07. Fixed point stacks under groups of multiplicative type. https://arxiv.org/abs/2101.02450

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