特殊测试配置与 Fano 簇的 $K$-稳定性
代数几何
2013-10-15 v3 微分几何
摘要
对于任意平坦射影族 ,若其一般纤维 是 klt Q-Fano 簇且 ,我们使用来自极小模型纲领 (MMP) 的技术来修改全族。最终得到的族使得每条纤维均为 klt Q-Fano 簇。此外,我们可以证明所出现模型的 Donaldson-Futaki 不变量是递减的。当该族是固定 Fano 簇 的一个测试配置时,这蕴含了 Tian 猜想:给定 Fano 流形 ,为测试其 K-(半, 多)稳定性,只需在特殊测试配置上进行测试。
引用
@article{arxiv.1111.5398,
title = {Special test configurations and $K$-stability of Fano varieties},
author = {Chi Li and Chenyang Xu},
journal= {arXiv preprint arXiv:1111.5398},
year = {2013}
}
备注
v3: Final version. To appear Annals of Mathematics. v2: 26 pages. The restriction that Picard number of the Fano variety equals one is removed by proving general facts on the Q-Fano degeneration of a (punctured) family of Q-Fano varieties. So a full version of Tian's conjecture is proved. The calculation on the decreasing of Donaldson-Futaki intersection number is streamlined