Moduli of Persson surfaces: The compactification via KSBA stable pairs and a generic global Torelli type theorem

Fuente: arXiv
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Main Authors: Fang, Hanlong, Nguyen, Bin, Wu, Xian, Zhang, Zheng
Format: Preprint
Published: 2026
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author Fang, Hanlong
Nguyen, Bin
Wu, Xian
Zhang, Zheng
author_facet Fang, Hanlong
Nguyen, Bin
Wu, Xian
Zhang, Zheng
contents We study a family of canonically polarized surfaces introduced by Persson, which arise as Galois $G=(\mathbb{Z}/2\mathbb{Z})^4$-covers of $\mathbf{P}^2$ branched along eight general lines. For this family, we construct the compactified moduli space and explicitly describe the stable degenerations in the sense of Kollár, Shepherd-Barron, and Alexeev (KSBA) via stable pairs of weighted hyperplane arrangements. By computing the $\mathbb{Q}$-Gorenstein obstructions and using the KSBA wall crossings, we show that the resulting compactified moduli stack is smooth. Furthermore, we establish a generic global Torelli type result: up to two possibilities, a generic smooth Persson surface can be recovered from the Hodge structure on the anti-invariant part of the second cohomology of its étale double cover, together with the associated $\widetilde{G}=(\mathbb{Z}/2\mathbb{Z})^5$-action.
format Preprint
id arxiv_https___arxiv_org_abs_2605_17223
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Moduli of Persson surfaces: The compactification via KSBA stable pairs and a generic global Torelli type theorem
Fang, Hanlong
Nguyen, Bin
Wu, Xian
Zhang, Zheng
Algebraic Geometry
We study a family of canonically polarized surfaces introduced by Persson, which arise as Galois $G=(\mathbb{Z}/2\mathbb{Z})^4$-covers of $\mathbf{P}^2$ branched along eight general lines. For this family, we construct the compactified moduli space and explicitly describe the stable degenerations in the sense of Kollár, Shepherd-Barron, and Alexeev (KSBA) via stable pairs of weighted hyperplane arrangements. By computing the $\mathbb{Q}$-Gorenstein obstructions and using the KSBA wall crossings, we show that the resulting compactified moduli stack is smooth. Furthermore, we establish a generic global Torelli type result: up to two possibilities, a generic smooth Persson surface can be recovered from the Hodge structure on the anti-invariant part of the second cohomology of its étale double cover, together with the associated $\widetilde{G}=(\mathbb{Z}/2\mathbb{Z})^5$-action.
title Moduli of Persson surfaces: The compactification via KSBA stable pairs and a generic global Torelli type theorem
topic Algebraic Geometry
url https://arxiv.org/abs/2605.17223