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Related papers: Rational surfaces in index-one Fano hypersurfaces

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We prove divisorial canonicity of Fano hypersurfaces and double spaces of general position with elementary singularities.

Algebraic Geometry · Mathematics 2008-07-25 Aleksandr Pukhlikov

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

We study the dominant rational maps from a general surface in P^{3} to surfaces of general type. We prove restrictions on the target surfaces, and special properties of the rational maps. We show that for a small degree the general surface…

Algebraic Geometry · Mathematics 2007-08-20 Lucio Guerra , Gian Pietro Pirola

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

Manin's conjecture predicts the distribution of rational points on Fano varieties. Using explicit parameterizations of rational points by integral points on universal torsors and lattice-point-counting techniques, it was proved for several…

Number Theory · Mathematics 2015-07-21 Christopher Frei , Marta Pieropan

We state conditions under which the set S(k) of k-rational points on a del Pezzo surface S of degree 1 over an infinite field k of characteristic not equal to 2 or 3 is Zariski dense. For example, it suffices to require that the elliptic…

Algebraic Geometry · Mathematics 2014-03-27 Cecilia Salgado , Ronald van Luijk

We give examples of K-unstable singular del Pezzo surfaces which are weighted hypersurfaces with index 2.

Algebraic Geometry · Mathematics 2020-11-10 In-kyun Kim , Joonyeong Won

The main aim of this article is to show that a very general 3-dimensional del Pezzo fibration of degree 1,2,3 is not stably rational except for a del Pezzo fibration of degree 3 belonging to explicitly described 2 families. Higher…

Algebraic Geometry · Mathematics 2017-01-31 Igor Krylov , Takuzo Okada

We consider threefold del Pezzo fibrations over a curve germ whose central fiber is non-rational. Under the additional assumption that the singularities of the total space are at worst ordinary double points, we apply a suitable base change…

Algebraic Geometry · Mathematics 2019-07-12 Konstantin Loginov

For a Zariski general (regular) hypersurface $V$ of degree $M$ in the $(M+1)$-dimensional projective space, where $M$ is at least 16, with at most quadratic singularities of rank at least 13, we give a complete description of the structures…

Algebraic Geometry · Mathematics 2017-12-27 Aleksandr V. Pukhlikov

This is a survey on the Fano schemes of linear spaces, conics, rational curves, and curves of higher genera in smooth projective hypersurfaces, complete intersections, Fano threefolds, etc.

Algebraic Geometry · Mathematics 2020-07-02 Ciro Ciliberto , Mikhail Zaidenberg

The purpose of this note is to show that the minimal $e$ for which every smooth Fano hypersurface of dimension $n$ contains a free rational curve of degree at most $e$ cannot be bounded by a linear function in $n$ when the base field has…

Algebraic Geometry · Mathematics 2026-03-10 Raymond Cheng

We prove birational superrigidity of Fano cyclic covers of index 1 over hypersurfaces in the projective space.

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

An asymptotic formula is established for the number of rational points of bounded height on a non-singular quartic del Pezzo surface with a conic bundle structure.

Number Theory · Mathematics 2019-12-19 T. D. Browning , R. de la Bretèche

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

Let $X$ be a smooth Fano threefold. We show that $X$ admits a non-isomorphic surjective endomorphism if and only if $X$ is either a toric variety or a product of $\mathbb{P}^1$ and a del Pezzo surface; in this case, $X$ is a rational…

Algebraic Geometry · Mathematics 2022-08-11 Sheng Meng , De-Qi Zhang , Guolei Zhong

Let X be a projective cubic hypersurface of dimension 11 or more, which is defined over the rationals. In this paper it is shown that X contains rational points provided that the cubic form defining X can be written as the sum of two forms…

Number Theory · Mathematics 2019-02-20 T. D. Browning

It is conjectured that a Fano manifold of Picard number 1 which is not a projective space admits no endomorphisms of degree bigger than 1. Beauville confirmed this for hypersurfaces of projective space. We study this problem for…

Algebraic Geometry · Mathematics 2009-07-22 Insong Choe

Let $W\subset \mathbb{P}^{13}$ be the image of the rational map defined by the linear system of the sextic surfaces of $\mathbb{P}^3$ having double points along the edges of a tetrahedron. Let $\mathcal{L}$ be the linear system of the…

Algebraic Geometry · Mathematics 2021-07-12 Vincenzo Martello

Given a nonsingular quartic del Pezzo surface, a conjecture of Manin predicts the density of rational points on the open subset of the surface formed by deleting the lines. We prove that this prediction is of the correct order of magnitude…

Algebraic Geometry · Mathematics 2015-05-13 Fok-Shuen Leung