English

Wall crossing for K-moduli spaces of plane curves

Algebraic Geometry 2024-05-01 v2 Differential Geometry

Abstract

We construct proper good moduli spaces parametrizing K-polystable Q\mathbb{Q}-Gorenstein smoothable log Fano pairs (X,cD)(X, cD), where XX is a Fano variety and DD is a rational multiple of the anti-canonical divisor. We then establish a wall-crossing framework of these K-moduli spaces as cc varies. The main application in this paper is the case of plane curves of degree d4d \geq 4 as boundary divisors of P2\mathbb{P}^2. In this case, we show that when the coefficient cc is small, the K-moduli space of these pairs is isomorphic to the GIT moduli space. We then show that the first wall crossing of these K-moduli spaces are weighted blow-ups of Kirwan type. We also describe all wall crossings for degree 4,5,6, and relate the final K-moduli spaces to Hacking's compactification and the moduli of K3 surfaces.

Keywords

Cite

@article{arxiv.1909.04576,
  title  = {Wall crossing for K-moduli spaces of plane curves},
  author = {Kenneth Ascher and Kristin DeVleming and Yuchen Liu},
  journal= {arXiv preprint arXiv:1909.04576},
  year   = {2024}
}

Comments

V2: 94 pages. Many typos fixed, and proofs of Theorems 5.2, 5.14, and 5.15 have been clarified (Lemma 5.16 is new). Postscript added (Remark 1.9) to discuss progress in K-moduli since the first version of this paper. To appear in Proceedings of the London Math Society