English

On positivity of the CM line bundle on K-moduli spaces

Algebraic Geometry 2021-02-22 v3 Differential Geometry

Abstract

In this paper, we consider the CM line bundle on the K-moduli space, i.e., the moduli space parametrizing K-polystable Fano varieties. We prove it is ample on any proper subspace parametrizing reduced uniformly K-stable Fano varieties which conjecturally should be the entire moduli space. As a corollary, we prove that the moduli space parametrizing smoothable K-polystable Fano varieties is projective. During the course of proof, we develop a new invariant for filtrations which can be used to test various K-stability notions of Fano varieties.

Keywords

Cite

@article{arxiv.1912.12961,
  title  = {On positivity of the CM line bundle on K-moduli spaces},
  author = {Chenyang Xu and Ziquan Zhuang},
  journal= {arXiv preprint arXiv:1912.12961},
  year   = {2021}
}

Comments

52 pages; v3: final version, to appear in Ann. of Math