English
Related papers

Related papers: Some criteria for uniform K-stability

200 papers

We show relationships between uniform K-stability and plt blowups of log Fano pairs. We see that it is enough to evaluate certain invariants defined by volume functions for all plt blowups in order to test uniform K-stability of log Fano…

Algebraic Geometry · Mathematics 2019-07-17 Kento Fujita

We give a simple necessary and sufficient condition for uniform K-stability of $\mathbb{Q}$-Fano varieties.

Algebraic Geometry · Mathematics 2016-09-20 Kento Fujita

We show that uniform K-stability is a Zariski open condition in Q-Gorenstein families of Q-Fano varieties. To prove this result, we consider the behavior of the stability threshold in families. The stability threshold (also known as the…

Algebraic Geometry · Mathematics 2020-06-11 Harold Blum , Yuchen Liu

We prove that on any log Fano pair of dimension $n$ whose stability threshold is less than $\frac{n+1}{n}$, any valuation computing the stability threshold has a finitely generated associated graded ring. Together with earlier works, this…

Algebraic Geometry · Mathematics 2022-02-15 Yuchen Liu , Chenyang Xu , Ziquan Zhuang

We prove that a log Fano cone $(X,\Delta,\xi_0)$ satisfying $\delta_\mathbb{T}(X,\Delta,\xi_0)\ge 1$ is K-polystable for normal test configurations if and only if it is K-polystable for special test configurations. We also establish the…

Algebraic Geometry · Mathematics 2026-03-26 Linsheng Wang

We give an algebraic proof of the equivalence of equivariant K-semistability (resp. equivariant K-polystability) with geometric K-semistability (resp. geometric K-polystability). Along the way we also prove the existence and uniqueness of…

Algebraic Geometry · Mathematics 2021-09-22 Ziquan Zhuang

We provide a sufficient condition for polarisations of Fano varieties to be K-stable in terms of Tian's alpha invariant, which uses the log canonical threshold to measure singularities of divisors in the linear system associated to the…

Algebraic Geometry · Mathematics 2016-04-21 Ruadhaí Dervan

Tian's criterion for K-stability states that a Fano variety of dimension $n$ whose alpha invariant is greater than $\frac{n}{n+1}$ is K-stable. We show that this criterion is sharp by constructing singular Fano varieties with alpha…

Algebraic Geometry · Mathematics 2020-08-06 Yuchen Liu , Ziquan Zhuang

For a variety $X$, a big $\mathbb{Q}$-divisor $L$ and a closed connected subgroup $G \subset \mathrm{Aut}(X, L)$ we define a $G$-invariant version of the $\delta$-threshold. We prove that for a Fano variety $(X, -K_X)$ and a connected…

Algebraic Geometry · Mathematics 2020-08-27 Aleksei Golota

We apply a recent theorem of Li and the first author to give some criteria for the K-stability of Fano varieties in terms of anticanonical Q-divisors. First, we propose a condition in terms of certain anticanonical Q-divisors of given Fano…

Algebraic Geometry · Mathematics 2016-11-01 Kento Fujita , Yuji Odaka

In this paper, we develop an algebraic K-stability theory (e.g. special test configuration theory and optimal destabilization theory) for log Fano $\mathbb R$-pairs, and construct a proper K-moduli space to parametrize K-polystable log Fano…

Algebraic Geometry · Mathematics 2024-12-23 Yuchen Liu , Chuyu Zhou

We show that G-equivariant K-semistability (resp. G-equivariant K-polystability) implies K-semistability (resp. K-polystability) for log Fano pairs when G is a finite group.

Algebraic Geometry · Mathematics 2020-01-30 Yuchen Liu , Ziwen Zhu

We prove a criterion for K-stability of a $\mathbb{Q}$-Fano spherical variety with respect to equivariant special test configurations, in terms of its moment polytope and some combinatorial data associated to the open orbit. Combined with…

Algebraic Geometry · Mathematics 2020-09-16 Thibaut Delcroix

We prove the following result: if a $\mathbb{Q}$-Fano variety is uniformly K-stable, then it admits a K\"{a}hler-Einstein metric. We achieve this by modifying Berman-Boucksom-Jonsson's strategy with appropriate perturbative arguments and…

Differential Geometry · Mathematics 2021-03-30 Chi Li , Gang Tian , Feng Wang

We introduce a norm on the space of test configurations, which we call the minimum norm. We conjecture that uniform K-stability with respect to this norm is equivalent to the existence of a constant scalar curvature K\"ahler metric. This…

Differential Geometry · Mathematics 2015-06-22 Ruadhaí Dervan

Let ${\rm k}$ be an algebraically closed field of characteristic 0 and $G$ a connect, reductive group over it. Let $X$ be a projective $G$-variety of complexity 1. We classify $G$-equivariant normal test configurations of $X$ with integral…

Algebraic Geometry · Mathematics 2025-10-24 Yan Li , Zhenye Li

We show that for a K-unstable Fano variety, any divisorial valuation computing its stability threshold induces a non-trivial special test configuration preserving the stability threshold. When such a divisorial valuation exists, we show…

Algebraic Geometry · Mathematics 2022-12-21 Harold Blum , Yuchen Liu , Chuyu Zhou

We give a lower bound of the $\delta$-invariants of ample line bundles in terms of Seshadri constants. As applications, we prove the uniform K-stability of infinitely many families of Fano hypersurfaces of arbitrarily large index, as well…

Algebraic Geometry · Mathematics 2022-04-28 Hamid Abban , Ziquan Zhuang

We develop a general approach to prove K-stability of Fano varieties. The new theory is used to (a) prove the existence of K\"ahler-Einstein metrics on all smooth Fano hypersurfaces of Fano index two, (b) to compute the stability thresholds…

Algebraic Geometry · Mathematics 2022-06-15 Hamid Abban , Ziquan Zhuang

We prove several boundedness results for log Fano pairs with certain K-stability. In particular, we prove that K-semistable log Fano pairs of Maeda type form a log bounded family. We also compute K-semistable domains for some examples.

Algebraic Geometry · Mathematics 2025-01-07 Konstantin Loginov , Chuyu Zhou
‹ Prev 1 2 3 10 Next ›