English
Related papers

Related papers: RDP del Pezzo surfaces with global vector fields i…

200 papers

Let $\Bbbk$ be any field of characteristic zero, $X$ be a del Pezzo surface and $G$ be a finite subgroup in $\operatorname{Aut}(X)$. In this paper we study when the quotient surface $X / G$ can be non-rational over $\Bbbk$. Obviously, if…

Algebraic Geometry · Mathematics 2019-06-11 Andrey Trepalin

Let $R = W(k)$ be the ring of Witt vectors over an algebraically closed field $k$ of characteristic $p > 2$. Let $M$ be a three-dimensional regular integral flat projective $R$-scheme such that $H^0(M,\mathcal{O}_M) = R$ and the…

Algebraic Geometry · Mathematics 2026-01-22 Hirotaka Onuki

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

We prove that del Pezzo surfaces of degree $2$ over a field $k$ satisfy weak weak approximation if $k$ is a number field and the Hilbert property if $k$ is Hilbertian of characteristic zero, provided that they contain a $k$-rational point…

Algebraic Geometry · Mathematics 2024-04-23 Julian Lawrence Demeio , Sam Streeter , Rosa Winter

The global log canonical threshold of each non-singular complex del Pezzo surface was computed by Cheltsov. The proof used Koll\'ar-Shokurov's connectedness principle and other results relying on vanishing theorems of Kodaira type, not…

Algebraic Geometry · Mathematics 2016-07-12 Jesus Martinez-Garcia

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 construct a klt del Pezzo surface which is not globally F-split, over any algebraically closed field of positive characteristic.

Algebraic Geometry · Mathematics 2016-01-15 Paolo Cascini , Hiromu Tanaka , Jakub Witaszek

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

Varieties of minimal degree and del Pezzo varieties are basic objects in projective algebraic geometry. Those varieties have been characterized and classified for a long time in many aspects. Motivated by the question "which varieties are…

Algebraic Geometry · Mathematics 2025-12-17 Jong In Han , Sijong Kwak , Euisung Park

We give a correspondence which associates, to any Del Pezzo surface X of degree 6 over a field k of characteristic 0, a collection of data consisting of a Severi-Brauer variety/k and a set of points defined over some extension of k.

Algebraic Geometry · Mathematics 2007-05-23 Patrick Corn

We settle a question that originates from results and remarks by Koll\'ar on extremal ray in the minimal model program: In positive characteristics, there are no Mori fibrations on threefolds with only terminal singularities whose generic…

Algebraic Geometry · Mathematics 2021-10-04 Andrea Fanelli , Stefan Schröer

We classify equivariantly Gorenstein log del Pezzo surfaces with boundaries at infinity and with finite group actions such that the quotient surface modulo the finite group has Picard number one. We also determine the corresponding finite…

Algebraic Geometry · Mathematics 2007-05-23 Masayoshi Miyanishi , De-Qi Zhang

We address weak approximation for certain del Pezzo surfaces defined over the function field of a curve. We study the rational connectivity of the smooth locus of degree two del Pezzo surfaces with two A1 singularities in order to prove…

Algebraic Geometry · Mathematics 2008-09-09 Amanda Knecht

We classify smooth del Pezzo surfaces whose alpha-invariant of Tian is bigger than one.

Algebraic Geometry · Mathematics 2011-01-12 Ivan Cheltsov , Andrew Wilson

Working over a perfect field, I classify normal del Pezzo surfaces with base number one that contain a nonrational singularity. They form a huge infinite hierarchy; contractions of ruled surfaces lie on top of it. Descending the hierarchy…

Algebraic Geometry · Mathematics 2007-05-23 Stefan Schroeer

In this article, we give the classification of normal del Pezzo surfaces of rank one with at most log canonical singularities containing the affine plane defined over an algebraically non-closed field of characteristic zero. As an…

Algebraic Geometry · Mathematics 2023-03-24 Masatomo Sawahara

This paper studies reduced, connected, Gorenstein surfaces with ample -K, assumed to be reducible or nonnormal. The normalisation is a union of one or more standard surfaces (scrolls and Veronese surfaces), marked with a conic as double…

alg-geom · Mathematics 2008-02-03 Miles Reid

Given a del Pezzo surface of degree d between 1 and 6, possibly with rational double points, we construct a "tautological" holomorphic G-bundle over X, where G is a reductive group which is an appropriate conformal form of the simply…

Algebraic Geometry · Mathematics 2007-05-23 Robert Friedman , John W. Morgan

Let $X$ be a del Pezzo surface of degree one over an algebraically closed field $k$, and let $K_X$ be its canonical divisor. The morphism $\varphi$ induced by the linear system $|-2K_X|$ realizes $X$ as a double cover of a cone in…

Algebraic Geometry · Mathematics 2022-09-29 Ronald van Luijk , Rosa Winter

We determine which singular del Pezzo surfaces are equivariant compactifications of G_a^2, to assist with proofs of Manin's conjecture for such surfaces. Additionally, we give an example of a singular quartic del Pezzo surface that is an…

Algebraic Geometry · Mathematics 2010-03-15 Ulrich Derenthal , Daniel Loughran