English

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

Algebraic Geometry 2026-05-19 v1

Abstract

We study a family of canonically polarized surfaces introduced by Persson, which arise as Galois G=(Z/2Z)4G=(\mathbb{Z}/2\mathbb{Z})^4-covers of P2\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 Koll\'ar, Shepherd-Barron, and Alexeev (KSBA) via stable pairs of weighted hyperplane arrangements. By computing the Q\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 \'etale double cover, together with the associated G~=(Z/2Z)5\widetilde{G}=(\mathbb{Z}/2\mathbb{Z})^5-action.

Keywords

Cite

@article{arxiv.2605.17223,
  title  = {Moduli of Persson surfaces: The compactification via KSBA stable pairs and a generic global Torelli type theorem},
  author = {Hanlong Fang and Bin Nguyen and Xian Wu and Zheng Zhang},
  journal= {arXiv preprint arXiv:2605.17223},
  year   = {2026}
}

Comments

37 pages, 8 figures. Comments are welcome