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Related papers: Fano varieties in Mori fibre spaces

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We describe a method to construct completions of affine spaces into total spaces of $\mathbb{Q}$-factorial terminal Mori fiber spaces over the projective line. As an application we provide families of examples with non-rational,…

Algebraic Geometry · Mathematics 2021-11-25 Adrien Dubouloz , Takashi Kishimoto , Karol Palka

Let $f\colon X\to Z$ be a Mori fibre space. McKernan conjectured that the singularities of $Z$ are bounded in terms of the singularities of $X$. Shokurov generalised this to pairs: let $(X,B)$ be a klt pair and $f\colon X\to Z$ a…

Algebraic Geometry · Mathematics 2012-10-10 Caucher Birkar

This paper is devoted to the study of various aspects of deformations of log pairs, especially in connection to questions related to the invariance of singularities and log plurigenera. In particular, using recent results from the minimal…

Algebraic Geometry · Mathematics 2009-06-24 Tommaso de Fernex , Christopher D. Hacon

In our previous work we conjectured - inspired by an algebro-geometric result of Fujita - that the height of an arithmetic Fano variety X of relative dimension $n$ is maximal when X is the projective space $\mathbb{P}^n_{\mathbb{Z}}$ over…

Algebraic Geometry · Mathematics 2024-03-05 Rolf Andreasson , Robert J. Berman

It is pretty well-known that toric Fano varieties of dimension k with terminal singularities correspond to convex lattice polytopes P in R^k of positive finite volume, such that intersection of P and Z^k consists of the point 0 and vertices…

Algebraic Geometry · Mathematics 2007-05-23 Alexandr Borisov

We give a brief survey of the concept of birational rigidity, from its origins in the two-dimensional birational geometry, to its current state. The main ingredients of the method of maximal singularities are discussed. The principal…

Algebraic Geometry · Mathematics 2007-05-23 Aleksandr V. Pukhlikov

We give a necessary and sufficient condition for the nonsingular projective toric variety associated to a finite simple graph to be Fano or weak Fano in terms of the graph.

Algebraic Geometry · Mathematics 2016-05-17 Yusuke Suyama

The fundamental property of Fano varieties with mild singularities is that they have a finite polyhedral Mori cone. Thus, it is very interesting to ask: What we can say about algebraic varieties with a finite polyhedral Mori cone? I give a…

Algebraic Geometry · Mathematics 2007-05-23 Viacheslav V. Nikulin

We establish birational superrigidity for a large class of singular projective Fano hypersurfaces of index one. In the special case of isolated singularities, our result applies for instance to: (1) hypersurfaces with semi-homogeneous…

Algebraic Geometry · Mathematics 2016-04-07 Tommaso de Fernex

It is proved that a general Fano hypersurface of index 1 (in the projective space) with isolated singularities of general position is birationally rigid. Therefore it cannot be fibered into uniruled varieties of a smaller dimension by a…

Algebraic Geometry · Mathematics 2015-06-26 Aleksandr V. Pukhlikov

We list combinatorial criteria of some singularities, which appear in the Minimal Model Program or in the study of (singular) Fano varieties, for spherical varieties. Most of the results of this paper are already known or are quite easy…

Algebraic Geometry · Mathematics 2015-10-15 Boris Pasquier

We prove that a general rational smooth Fano threefold admits a toric model. More precisely, for a general rational smooth Fano threefold $X$, we show the existence of a boundary divisor $D$ for which $(X,D)\simeq_{\rm cbir}…

Algebraic Geometry · Mathematics 2024-07-15 Konstantin Loginov , Joaquín Moraga , Artem Vasilkov

We revisit results of Fujino--Sato on complete non-projective $\mathbb Q$-factorial toric varieties and their conjectural factorization by flips. We show that their main results admit short conceptual proofs, avoiding any restriction on the…

Algebraic Geometry · Mathematics 2026-02-27 Michele Rossi

Inspired by Fujita's algebro-geometric result that complex projective space has maximal degree among all K-semistable complex Fano varieties, we conjecture that the height of a K-semistable metrized arithmetic Fano variety X of relative…

Algebraic Geometry · Mathematics 2024-11-20 Rolf Andreasson , Robert J. Berman

We prove that the Fano variety of lines of a generic cubic fourfold containing a plane is isomorphic to a moduli space of twisted stable complexes on a K3 surface. On the other hand, we show that the Fano varieties are always birational to…

Algebraic Geometry · Mathematics 2011-12-26 Emanuele Macri , Paolo Stellari

Iterating the procedure of making a double cover over a given variety, we construct large families of smooth higher-dimensional Fano varieties of index 1. These varieties can be realized as complete intersections in various weighted…

Algebraic Geometry · Mathematics 2015-06-26 Aleksandr V. Pukhlikov

Motivated by the general question of existence of open A1-cylinders in higher dimensional pro-jective varieties, we consider the case of Mori Fiber Spaces of relative dimension three, whose general closed fibers are isomorphic to the…

Algebraic Geometry · Mathematics 2018-05-16 Adrien Dubouloz , Takashi Kishimoto

We prove that a general Fano fibration $\pi\colon V\to {\mathbb P}^1$, the fiber of which is a double Fano hypersurface of index 1, is birationally superrigid provided it is sufficiently twisted over the base. In particular, on $V$ there…

Algebraic Geometry · Mathematics 2007-05-23 Aleksandr V. Pukhlikov

Using deformation theory of rational curves, we prove a conjecture of Sommese on the extendability of morphisms from ample subvarieties when the morphism is a smooth (or mildly singular) fibration with rationally connected fibers. We apply…

Algebraic Geometry · Mathematics 2020-11-23 Tommaso de Fernex , Chung Ching Lau

In this short note we show the unboundedness of the dimension of the K-moduli space of $n$-dimensional Fano varieties, and that the dimension of the stack can also be unbounded while, simultaneously, the dimension of the corresponding…

Algebraic Geometry · Mathematics 2021-01-15 Jesus Martinez-Garcia , Cristiano Spotti