English
Related papers

Related papers: Double quadrics with large automorphism groups

200 papers

The aim of this work is to provide the first examples of $n$-dimensional varieties of wild representation type, for arbitrary $n\geq 2$. More precisely, we prove that all Fano blow-ups of $\PP^n$ at a finite number of points are of wild…

Algebraic Geometry · Mathematics 2010-11-17 Rosa M. Miró-Roig Joan Pons-Llopis

This paper explores the Fano variety of lines in hypersurfaces, particularly focusing on those with mild singularities. Our first result explores the irreducibility of the variety $\Sigma$ of lines passing through a singular point $y$ on a…

Algebraic Geometry · Mathematics 2025-03-12 Jiayi Hu , Fengyang Wang , Xinlang Zhu

Let $A$ be an abelian variety over an algebraically closed field. We show that $A$ is the automorphism group scheme of some smooth projective variety if and only if $A$ has only finitely many automorphisms as an algebraic group. This…

Algebraic Geometry · Mathematics 2021-05-24 Jérémy Blanc , Michel Brion

It is shown that the automorphism group of a binary $q$-analog of the Fano plane is either trivial or of order $2$.

Combinatorics · Mathematics 2017-05-03 Michael Kiermaier , Sascha Kurz , Alfred Wassermann

We study linearizability of actions of finite groups on cubic threefolds with nonnodal isolated singularities.

Algebraic Geometry · Mathematics 2025-11-14 Ivan Cheltsov , Lisa Marquand , Yuri Tschinkel , Zhijia Zhang

We show that Fano lattice polygons define a class of balanced quivers with interesting properties. The combinatorics of these quivers is related to singularities of the underlying toric Fano surface. This allows us to show that every Fano…

Algebraic Geometry · Mathematics 2019-07-23 Mohammad E. Akhtar

We classify all $\mathbb{Q}$-factorial Fano intrinsic quadrics of dimension three and Picard number one having at most canonical singularities.

Algebraic Geometry · Mathematics 2020-05-26 Christoff Hische

It is known that the canonical double cover of any connected nonbipartite graph have an automorphism group of the form $H \rtimes \mathbb{Z}_2$, where $H$ is the set of automorphism which preserve bipartite parts. We construct connected…

Combinatorics · Mathematics 2024-06-11 Bartłomiej Bychawski

Let $X$, $Y$ be Fano threefolds of Picard number one and such that the ample generators of Picard groups are very ample. Let $X$ be of index one and $Y$ be of index two. It is shown that the only morphisms from $X$ to $Y$ are double…

Algebraic Geometry · Mathematics 2007-05-23 Ekaterina Amerik

We study quartic double fivefolds from the perspective of Fano manifolds of Calabi-Yau type and that of exceptional quaternionic representations. We first prove that the generic quartic double fivefold can be represented, in a finite number…

Algebraic Geometry · Mathematics 2017-10-13 Roland Abuaf

We study automorphism groups of fibered surfaces for finite cyclic covering fibrations of an elliptic surface. We estimate the order of a finite subgroup of automorphism groups in terms of the genus of the fiber, the genus of the base…

Algebraic Geometry · Mathematics 2023-04-18 Hiroto Akaike

General linear sections of codimension 2 of the Grassmannians G(1,4) and G(1,5) appear in the classification of Fano manifolds of high index. Unlike Grassmannians, these manifolds are not homogeneous. Nevertheless, their automorphisms…

Algebraic Geometry · Mathematics 2015-05-26 Rafael Lucas de Arruda

We classify Fano fivefolds of index two which are blow-ups of smooth manifolds along a smooth center.

Algebraic Geometry · Mathematics 2017-09-29 Elena Chierici , Gianluca Occhetta

We establish the vanishing of the third unramified cohomology group for many types of Fano hypersurfaces in projective space over an algebraically closed field of arbitrary characteristic, and over a finite field. For cubic hypersurfaces…

Algebraic Geometry · Mathematics 2017-10-18 Jean-Louis Colliot-Thélène

We study global log canonical thresholds on anticanonically embedded quasismooth weighted Fano threefold hypersurfaces having terminal quotient singularities to prove the existence of a Kahler-Einstein metric on most of them, and to produce…

Algebraic Geometry · Mathematics 2007-06-18 Ivan Cheltsov

We prove birational superrigidity of Fano double hypersurfaces of index one with quadratic and multi-quadratic singularities, satisfying certain regularity conditions, and give an effective explicit lower bound for the codimension of the…

Algebraic Geometry · Mathematics 2018-12-31 Thomas Eckl , Aleksandr Pukhlikov

In this paper, we develop a new method to classify abelian automorphism groups of hypersurfaces. We use this method to classify (Theorem 4.2) abelian groups that admit a liftable action on a smooth cubic fourfold. A parallel result (Theorem…

Algebraic Geometry · Mathematics 2021-09-07 Tianzhen Peng , Zhiwei Zheng

We propose a new method to study birational maps between Fano varieties based on multiplier ideal sheaves. Using this method, we prove equivariant birational rigidity of four Fano threefolds acted on by the group A6. As an application, we…

Algebraic Geometry · Mathematics 2011-12-08 Ivan Cheltsov , Constantin Shramov

O'Grady showed that certain special sextics in $\mathbb{P}^5$ called EPW sextics admit smooth double covers with a holomorphic symplectic structure. We propose another perspective on these symplectic manifolds, by showing that they can be…

Algebraic Geometry · Mathematics 2009-07-17 Atanas Iliev , Laurent Manivel

A Fano-Enriques threefold is a three-dimensional non-Gorenstein Fano variety of index 1 with at most canonical singularities. We study the birational geometry of Fano-Enriques threefolds with terminal cyclic quotient singularities. We…

Algebraic Geometry · Mathematics 2023-01-19 Arman Sarikyan