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Related papers: Weak del Pezzo surfaces with global vector fields

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We study the space of rational curves on del Pezzo surfaces in positive characteristic. For most primes p we prove the irreducibility of the moduli space of rational curves of a given nef class, extending results of Testa in characteristic…

Algebraic Geometry · Mathematics 2022-10-04 Roya Beheshti , Brian Lehmann , Eric Riedl , Sho Tanimoto

We give a complete classification of del Pezzo surfaces with quotient singularities and Picard rank 1 which admit a Q-Gorenstein smoothing. There are 14 infinite families of toric examples. The surfaces in each family correspond to…

Algebraic Geometry · Mathematics 2019-02-20 Paul Hacking , Yuri Prokhorov

We describe smooth rational projective algebraic surfaces over an algebraically closed field of characteristic different from 2 which contain $n \ge \b_2-2$ disjoint smooth rational curves with self-intersection -2, where $\b_2$ is the…

Algebraic Geometry · Mathematics 2007-05-23 Igor Dolgachev , Margarida Mendes Lopes , Rita Pardini

This is an expanded version of our work [AN88], 1988, in Russian. We classify del Pezzo surfaces over C with log terminal singularities of index \le 2. By classification, we understand a description of the intersection graph of all…

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

In these notes, we consider self-maps of degree > 1 on a weak del Pezzo surface X of degree < 8. We show that there are exactly 12 such X, modulo isomorphism. In particular, K_X^2 > 2, and if X has one self-map of degree > 1 then for every…

Algebraic Geometry · Mathematics 2018-06-20 D. -Q. Zhang

The surfaces considered are real, rational and have a unique smooth real $(-2)$-curve. Their canonical class $K$ is strictly negative on any other irreducible curve in the surface and $K^2>0$. For surfaces satisfying these assumptions, we…

Algebraic Geometry · Mathematics 2018-05-17 Ilia Itenberg , Viatcheslav Kharlamov , Eugenii Shustin

We study full exceptional collections of line bundles on surfaces. We prove that any full strong exceptional collection of line bundles on a weak del Pezzo surface of degree $\ge 3$ is an augmentation in the sense of L.Hille and M.Perling,…

Algebraic Geometry · Mathematics 2017-10-18 Alexey Elagin , Junyan Xu , Shizhuo Zhang

In this paper we obtain necessary and sufficient condition for existence of del Pezzo surfaces of degree $5$ and $6$ over a field $K$ with a prescribed action of absolute Galois group $\text{Gal} ( K^{\text{sep}}/K)$ on the graph of…

Algebraic Geometry · Mathematics 2024-02-06 Alexandr Zaitsev

For each field $k$ of characteristic zero, we classify which groups act by automorphisms on a quartic del Pezzo surface over $k$. We also determine which groups act on $k$-rational, stably $k$-rational, or $k$-unirational quartic del Pezzo…

Algebraic Geometry · Mathematics 2023-08-16 Jonathan M. Smith

We classify the number of $k$-rational lines and conic fibrations on del Pezzo surfaces over a field $k$ in terms of relatively minimal surfaces and establish rational curve analogues of the inverse Galois problem for del Pezzo surfaces. We…

Algebraic Geometry · Mathematics 2025-11-13 Enis Kaya , Stephen McKean , Sam Streeter , H. Uppal

We classify del Pezzo surfaces with Du Val singularities that have infinite automorphism groups, and describe the connected components of their automorphisms groups.

Algebraic Geometry · Mathematics 2020-10-02 Ivan Cheltsov , Yuri Prokhorov

We give a characterization of all del Pezzo surfaces of degree 6 over an arbitrary field $F$. A surface is determined by a pair of separable algebras. These algebras are used to compute the Quillen $K$-theory of the surface. As a…

Algebraic Geometry · Mathematics 2008-05-02 Mark Blunk

We provide explicit graded constructions of orbifold del Pezzo surfaces with rigid orbifold points of type $\left\{k_i\times\frac{1}{r_i}(1,a_i): 3\le r_i \le 10,k_i \in \ZZ_{\ge 0}\right\}$; as well-formed and quasismooth varieties…

Algebraic Geometry · Mathematics 2020-09-14 Muhammad Imran Qureshi

Let $X$ be a minimal del Pezzo surface of degree $2$ over a finite field $\mathbb{F}_q$. The image $\Gamma$ of the Galois group $\operatorname{Gal}(\overline{\mathbb{F}}_q / \mathbb{F}_q)$ in the group…

Algebraic Geometry · Mathematics 2017-09-08 Andrey Trepalin

Let $k$ be an algebraically closed field of characteristic $p>0$. Let $X$ be a normal projective surface over $k$ with canonical singularities whose anti-canonical divisor is nef and big. We prove that $X$ is globally $F$-regular except for…

Algebraic Geometry · Mathematics 2024-04-09 Tatsuro Kawakami , Hiromu Tanaka

We construct an example of a field and a del Pezzo surface of degree $2$ over this field without points such that its automorphism group is isomorphic to $\mathrm{PSL}_2(\mathbb{F}_7) \times \mathbb{Z}/2\mathbb{Z},$ which is the largest…

Algebraic Geometry · Mathematics 2025-01-28 Anastasia V. Vikulova

We study the groups of automorphisms of rational algebraic surfaces that admit a relatively minimal pencil of curves of arithmetic genus one over an algebraically closed field of arbitrary characteristic. In particular, we classify such…

Algebraic Geometry · Mathematics 2021-06-25 Igor Dolgachev , Gebhard Martin

We prove, via an "arithmetic surjectivity" approach inspired by work of Denef, that weak weak approximation holds for surfaces with two conic fibrations satisfying a general assumption. In particular, weak weak approximation holds for…

Algebraic Geometry · Mathematics 2023-05-08 Julian Lawrence Demeio , Sam Streeter

We construct a natural semiorthogonal decomposition for the derived category of an arbitrary flat family of sextic del Pezzo surfaces with at worst du Val singularities. This decomposition has three components equivalent to twisted derived…

Algebraic Geometry · Mathematics 2018-12-18 Alexander Kuznetsov

Among geometrically rational surfaces, del Pezzo surfaces of degree two over a field k containing at least one point are arguably the simplest that are not known to be unirational over k. Looking for k-rational curves on these surfaces, we…

Algebraic Geometry · Mathematics 2017-05-17 Cecília Salgado , Damiano Testa , Anthony Várilly-Alvarado