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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

We prove that every del Pezzo surface of degree two over a finite field is unirational, building on the work of Manin and an extension by Salgado, Testa, and V\'arilly-Alvarado, who had proved this for all but three surfaces. Over general…

Algebraic Geometry · Mathematics 2017-05-17 Dino Festi , Ronald van Luijk

We prove that every del Pezzo surface of degree two over a finite field is unirational, building on the work of Manin and an extension by Salgado, Testa, and V\'arilly-Alvarado, who had proved this for all but three surfaces. Over general…

Algebraic Geometry · Mathematics 2015-05-07 Dino Festi , Ronald van Luijk

We study unirationality of a Del Pezzo surface of degree two over a given (non algebraically closed) field, under the assumption that it admits at least one rational double point over an algebraic closure of the base field. As corollaries…

Algebraic Geometry · Mathematics 2021-07-13 Ryota Tamanoi

We give upper bounds for the number of rational points of bounded anti-canonical height on del Pezzo surfaces of degree at most five over any global field whose characteristic is not equal to two or three. For number fields these results…

Number Theory · Mathematics 2024-01-11 Jakob Glas , Leonhard Hochfilzer

We study degree two unirational parameterizations of geometrically rational surfaces over the real field.

Algebraic Geometry · Mathematics 2025-09-15 Brendan Hassett , Hayato Takagi , Sho Tanimoto

We discuss the rational points on del Pezzo surface of degree 1 and 2 over any finite field $\mathbb F_q$, and give out the explicit equations of del Pezzo surfaces that have unique rational point.

Algebraic Geometry · Mathematics 2011-04-27 Shuijing Li

Hirschfeld classified split del Pezzo surfaces of degree at least three whose points are all contained on the lines in the surface. We continue his work and begin the classification of split degree two del Pezzo surfaces over finite fields…

Algebraic Geometry · Mathematics 2016-04-12 Amanda Knecht , Kristofer Reyes

Sur toute surface de del Pezzo de degr\'e 4 sur un corps $C_1$ de caract\'eristique z\'ero, tous les points rationnels sont R-\'equivalents. Plus g\'en\'eralement, ceci vaut sur tout corps parfait infini de caract\'eristique diff\'erente de…

Algebraic Geometry · Mathematics 2015-09-22 Jean-Louis Colliot-Thélène

It is well known that every Del Pezzo surface of degree 5 defined over k is parametrizable over k. In this paper we give an efficient construction for parametrizing, as well as algorithms for constructing examples in every isomorphism class…

Algebraic Geometry · Mathematics 2011-05-18 Jon Gonzalez-Sanchez , Michael Harrison , Irene Polo-Blanco , Josef Schicho

In this paper we study quotients of del Pezzo surfaces of degree four and more over arbitrary field $\Bbbk$ of characteristic zero by finite groups of automorphisms. We show that if a del Pezzo surface $X$ contains a point defined over the…

Algebraic Geometry · Mathematics 2016-11-09 Andrey Trepalin

For an irreducible variety $X$ over a field $k$, the degree of irrationality $\operatorname{irr}_k X$ is the minimal degree of a dominant rational map $X \dashrightarrow \mathbb{P}_k^{\operatorname{\dim} X}$. When $X$ is a curve, this is…

Algebraic Geometry · Mathematics 2025-10-29 Adam Logan , Anthony Várilly-Alvarado , David Zureick-Brown

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

It is known that any Mori fiber space birational to a minimal smooth del Pezzo surface $S$ of degree $4$ is either a del Pezzo surface of degree $4$ itself, or a smooth cubic surface with a structure of a relatively minimal conic bundle. We…

Algebraic Geometry · Mathematics 2025-12-23 Constantin Shramov , Andrey Trepalin

For a Del Pezzo surface of degree 8 given over the rationals we decide whether there is a rational parametrization of the surface and construct one in the affirmative case. We define and use the Lie algebra of the surface to reach the aim.…

Algebraic Geometry · Mathematics 2007-05-23 Willem A. de Graaf , Jana Pílniková , Josef Schicho

We find normal forms for del Pezzo surfaces of degree $2$ over algebraically closed fields of characteristic $2$. For each normal form, we describe the structure of the group of automorphisms of the surface. In particular, we classify all…

Algebraic Geometry · Mathematics 2023-05-19 Igor Dolgachev , Gebhard Martin

In this article, we obtain an upper bound for the number of integral points on the del Pezzo surfaces of degree two.

Number Theory · Mathematics 2020-10-30 Aritra Ghosh , Sumit Kumar , Kummari Mallesham , Saurabh Kumar Singh

We classify the automorphism groups of del Pezzo surfaces of degrees one and two over an algebraically closed field of characteristic two. This finishes the classification of automorphism groups of del Pezzo surfaces in all characteristics.

Algebraic Geometry · Mathematics 2025-03-26 Igor Dolgachev , Gebhard Martin

We classify geometrically integral regular del Pezzo surfaces which are not geometrically normal over imperfect fields of positive characteristic. Based on this classification, we show that a three-dimensional terminal del Pezzo fibration…

Algebraic Geometry · Mathematics 2025-11-12 Fabio Bernasconi , Hiromu Tanaka

In this article we prove the following theorems about weak approximation of smooth cubic hypersurfaces and del Pezzo surfaces of degree 4 defined over global fields. (1) For cubic hypersurfaces defined over global function fields, if there…

Algebraic Geometry · Mathematics 2015-11-26 Letao Zhang , Zhiyu Tian
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