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Related papers: On weak Fano varieties with log canonical singular…

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We classify three-dimensional Fano varieties with canonical Gorenstein singularities of degree bigger than 64.

Algebraic Geometry · Mathematics 2015-05-13 Ilya Karzhemanov

We show that some properties of log canonical centers of a log canonical pair (X,D) also hold for certain subvarieties that are close to being a log canonical center. As a consequence, we obtain that if one works with deformations of pairs…

Algebraic Geometry · Mathematics 2011-05-20 János Kollár

We prove that the asymptotic base loci of an NQC klt generalized pair with big canonical class are uniruled. We also show that the non-nef locus and the diminished base locus of the adjoint divisor of an NQC log canonical generalized pair…

Algebraic Geometry · Mathematics 2024-04-26 Nikolaos Tsakanikas , Zhixin Xie

We solve the infinitesimal Torelli problem for $3$-dimensional quasi-smooth ${\mathbb{Q}}$-Fano hypersurfaces with at worst terminal singularities. We also find infinite chains of double coverings of increasing dimension which alternatively…

Algebraic Geometry · Mathematics 2019-02-15 Enrico Fatighenti , Luca Rizzi , Francesco Zucconi

We compute the cones of effective divisors on blowups of $\mathbb{P}^1 \times \mathbb{P}^2$ and $\mathbb{P}^1 \times \mathbb{P}^3$ in up to 6 points. We also show that all these varieties are log Fano, giving a conceptual explanation for…

Algebraic Geometry · Mathematics 2022-04-27 Tim Grange , Elisa Postinghel , Artie Prendergast-Smith

We prove that a log surface has only finitely many weakly log canonical projective models with klt singularities up to log isomorphism, by reducing the problem to the boundedness of their polarization.

Algebraic Geometry · Mathematics 2025-10-17 Daniil Serebrennikov

Let $X$ be a $\mathbb Q$-factorial canonical weak Fano variety of dimension $n\geq 2$. We show that if the $\mathbb Q$-Fano index $q_{\mathbb Q}(X)\geq 3$, then $X$ satisfies a Kawamata--Miyaoka type inequality: \[c_1(X)^n\leq 4\,\hat…

Algebraic Geometry · Mathematics 2025-11-18 Haidong Liu

We study the problem of uniformizing quasi-projective varieties with logcanonical compactifications. More precisely, given a complex projective variety X with log-canonical singularities, we give criteria for X to be isomorphic to a…

Algebraic Geometry · Mathematics 2024-09-02 Benoit Cadorel

Let $(X, \Delta)/U$ be klt pairs and $Q$ be a convex set of divisors. Assuming that the relative Kodaira dimensions are non-negative, then there are only finitely many log canonical models when the boundary divisors varying in a relatively…

Algebraic Geometry · Mathematics 2020-06-03 Zhan Li

In this note, we prove a sharp lower bound for the log canonical threshold of a plurisubharmonic function $\varphi$ with an isolated singularity at $0$ in an open subset of ${\mathbb C}^n$. This threshold is defined as the supremum of…

Complex Variables · Mathematics 2014-02-17 Jean-Pierre Demailly , Hoang Hiep Pham

We introduce the notion of potentially klt pairs for normal projective varieties with pseudoeffective anticanonical divisor. The potentially non-klt locus is a subset of $X$ which is birationally transformed precisely into the non-klt locus…

Algebraic Geometry · Mathematics 2016-06-10 Sung Rak Choi , Jinhyung Park

In this paper we study smooth projective rational surfaces, defined over an algebraically closed field of any characteristic, with pseudo-effective anticanonical divisor. We provide a necessary and sufficient condition in order for any nef…

Algebraic Geometry · Mathematics 2013-03-27 Antonio Laface , Damiano Testa

For a generic anti-canonical hypersurface in each smooth toric Fano 4-fold with rank 2 Picard group, we prove there exist three isolated rational curves in it. Moreover, for all these 4-folds except one, the contractions of generic…

Algebraic Geometry · Mathematics 2010-12-21 Jinxing Xu

We show that the family of semi log canonical pairs with ample log canonical class and with fixed volume is bounded.

Algebraic Geometry · Mathematics 2017-09-22 Christopher Hacon , James McKernan , Chenyang Xu

We investigate birational boundedness of Fano varieties and Fano fibrations. We establish an inductive step towards birational boundedness of Fano fibrations via conjectures related to boundedness of Fano varieties and Fano fibrations. As…

Algebraic Geometry · Mathematics 2019-12-02 Chen Jiang

The main purpose of this article is to prove that the family of all Fano threefolds with log-terminal singularities with bounded index is bounded.

alg-geom · Mathematics 2008-02-03 A. Borisov

A projective log variety (X, D) is called "a log Fano manifold" if X is smooth and if D is a reduced simple normal crossing divisor on X with -(K_X+D) ample. The n-dimensional log Fano manifolds (X, D) with nonzero D are classified in this…

Algebraic Geometry · Mathematics 2015-01-14 Kento Fujita

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

We construct well-formed and quasismooth terminal Fano 4-folds of index 1 in low codimension containing at worst isolated orbifold points. We provide a certain classification of these varieties where their images under the anitcanonical…

Algebraic Geometry · Mathematics 2025-06-30 Muhammad Imran Qureshi

This paper concerns the construction of minimal varieties with small canonical volumes. The first part devotes to establishing an effective nefness criterion for the canonical divisor of a weighted blow-up over a weighted hypersurface, from…

Algebraic Geometry · Mathematics 2024-06-05 Meng Chen , Chen Jiang , Binru Li