English
Related papers

Related papers: Note on K-stability of pairs

200 papers

Let $S$ be a smooth projective variety and $\Delta$ a simple normal crossing $\mathbb{Q}$-divisor with coefficients in $(0,1]$. For any ample $\mathbb{Q}$-line bundle $L$ over $S$, we denote by $\mathscr{E}(L)$ the extension sheaf of the…

Differential Geometry · Mathematics 2019-03-05 Chi Li

A variety is said to satisfy Condition (A) if every finite abelian subgroup of its automorphism group has a fixed point. We show that a smooth Fano 3-fold not satisfying Condition (A) is K-polystable unless it is contained in eight…

Algebraic Geometry · Mathematics 2025-05-08 Hamid Abban , Ivan Cheltsov , Takashi Kishimoto , Frederic Mangolte

We study Diophantine arithmetic properties of birational divisors in conjunction with concepts that surround $\mathrm{K}$-stability for Fano varieties. There is also an interpretation in terms of the barycentres of Newton-Okounkov bodies.…

Algebraic Geometry · Mathematics 2020-02-14 Nathan Grieve

We give a lower bound for the delta invariant of the fundamental divisor of a quasi-smooth weighted hypersurface. As a consequence, we prove K-stability of a large class of quasi-smooth Fano hypersurfaces of index 1 and of all smooth Fano…

Algebraic Geometry · Mathematics 2026-02-12 Taro Sano , Luca Tasin

A famous theorem of Shokurov states that a general anticanonical divisor of a smooth Fano threefold is a smooth K3 surface. This is quite surprising since there are several examples where the base locus of the anticanonical system has…

Algebraic Geometry · Mathematics 2025-04-16 Andreas Höring , Saverio Andrea Secci

We prove that all smooth Fano threefolds of rank 4 and degree 24 are K-stable.

Algebraic Geometry · Mathematics 2022-06-27 Grigory Belousov , Konstantin Loginov

Let $(X, \Delta)$ be a log Fano pair with standard coefficients endowed with a singular K\"ahler--Einstein metric. We show that the adapted tangent sheaf $\mathcal{T}_{X, \Delta, f}$ and the adapted canonical extension $\mathcal{E}_{X,…

Differential Geometry · Mathematics 2026-01-28 Louis Dailly

It is shown that any, possibly singular, Fano variety X admitting a Kahler-Einstein metric is K-polystable, thus confirming one direction of the Yau-Tian-Donaldson conjecture in the setting of Q-Fano varieties equipped with their…

Differential Geometry · Mathematics 2015-06-10 Robert J. Berman

In this paper, we prove the openness of K-semistability in families of log Fano pairs by showing that the stability threshold is a constructible function on the fibers. We also prove that any special test configuration arises from a log…

Algebraic Geometry · Mathematics 2021-11-02 Harold Blum , Yuchen Liu , Chenyang Xu

We study K-stability of products of K-stable $\mathbb{Q}$-Fano varieties.

Algebraic Geometry · Mathematics 2016-10-18 Jihun Park , Joonyeong Won

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

For any log Fano pair with a torus action, we associate a computable invariant to it, such that the pair is (weighted) K-polystable if and only if this invariant is greater than one. As an application, we present examples of Fano varieties…

Algebraic Geometry · Mathematics 2025-10-14 Linsheng Wang

We prove the conjectural Bogomolov-Gieseker type inequality for tilt slope stable objects on each Fano threefold X of Picard number one. Based on the previous works on Bridgeland stability conditions, this induces an open subset of…

Algebraic Geometry · Mathematics 2016-02-15 Chunyi Li

We interpret the coupled Ding semistability and the reduced coupled uniform Ding stability of log Fano pairs in the notion of coupled stability thresholds and reduced coupled stability thresholds. As a corollary, we solve a modified version…

Algebraic Geometry · Mathematics 2024-12-06 Kento Fujita , Yoshinori Hashimoto

For Fano varieties, significant progress has been made recently in the study of $K$-stability, while the understanding of the weaker but more algebraic concept of $(-K)$-slope stability remains intricate. For instance, a conjecture…

Algebraic Geometry · Mathematics 2026-01-27 Yen-An Chen , Ching-Jui Lai

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 show that any $n$-dimensional Fano manifold $X$ with $\alpha(X)=n/(n+1)$ and $n\geq 2$ is K-stable, where $\alpha(X)$ is the alpha invariant of $X$ introduced by Tian. In particular, any such $X$ admits K\"ahler-Einstein metrics and the…

Algebraic Geometry · Mathematics 2016-06-28 Kento Fujita

Let $X$ be a smooth complex projective rationally connected threefold with $-K_X$ nef and not semi-ample. In our previous work, we classified all such threefolds when $|{-}K_X|$ has no fixed divisor. In this paper, we continue our…

Algebraic Geometry · Mathematics 2023-01-24 Zhixin Xie

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

The main goal of this paper is to prove the polystability of the logarithmic tangent sheaf $\mathscr T_X(-D)$ of a log canonical pair $(X,D)$ whose canonical bundle $K_X+D$ is ample, generalizing in a significant way a theorem of Enoki. We…

Algebraic Geometry · Mathematics 2015-02-13 Henri Guenancia