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arXiv · 2505.22812

Moduli spaces for $\Theta$-strata and non-reductive quotients

Ludvig Modin
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Abstract

We give a new proof of the $\hat{U}$-theorem of B\'erczi, Doran, Hawes and Kirwan on the existence of geometric quotients for actions of graded unipotent groups in terms of stacks of filtrations and gradings introduced by Halpern-Leistner. Our proof works over any affine Noetherian base, in particular it simultaneously generalizes the previous results to arbitrary characteristic, actions in families and to general $\Theta$-strata.

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Ludvig Modin. 2025-05-28. Moduli spaces for $\Theta$-strata and non-reductive quotients. https://arxiv.org/abs/2505.22812

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