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arXiv · 2504.20312

Hassett--Keel Program in genus four

Kenneth Ascher·Kristin DeVleming·Yuchen Liu·Xiaowei Wang
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Abstract

The Hassett--Keel program seeks to give a modular interpretation to the steps of the log minimal model program of $\overline{\mathcal{M}}_g$. The goal of this paper is to complete the Hassett--Keel program in genus four, supplementing earlier results of Casalaina-Martin--Jensen--Laza and Alper--Fedorchuk--Smyth--van der Wyck. The main tools we use are wall crossing for moduli spaces of pairs in the sense of K-stability and KSBA stability, and the recently constructed moduli spaces of boundary polarized Calabi--Yau surface pairs. We also give a construction of the hyperelliptic flip using a stackified Chow quotient which is expected to generalize to higher genus.

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Kenneth Ascher, Kristin DeVleming, Yuchen Liu, Xiaowei Wang. 2025-04-28. Hassett--Keel Program in genus four. https://arxiv.org/abs/2504.20312

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