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Stratifying Quotient Stacks and Moduli Stacks

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Geometry of Moduli (Abelsymposium 2017)

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Abstract

Recent results in geometric invariant theory (GIT) for non-reductive linear algebraic group actions allow us to stratify quotient stacks of the form [XH], where X is a projective scheme and H is a linear algebraic group with internally graded unipotent radical acting linearly on X, in such a way that each stratum [SH] has a geometric quotient SH. This leads to stratifications of moduli stacks (for example, sheaves over a projective scheme) such that each stratum has a coarse moduli space.

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Acknowledgment

V.H. is supported by the Excellence Initiative of the DFG at the Freie Universität Berlin.

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Correspondence to Frances Kirwan .

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Bérczi, G., Hoskins, V., Kirwan, F. (2018). Stratifying Quotient Stacks and Moduli Stacks. In: Christophersen, J., Ranestad, K. (eds) Geometry of Moduli. Abelsymposium 2017. Abel Symposia, vol 14. Springer, Cham. https://doi.org/10.1007/978-3-319-94881-2_1

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