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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

Many classical results in algebraic geometry arise from investigating some extremal behaviors that appear among projective varieties not lying on any hypersurface of fixed degree. We study two numerical invariants attached to such…

Algebraic Geometry · Mathematics 2019-06-20 Edoardo Ballico , Emanuele Ventura

Given a generic semidefinite program, specified by matrices with rational entries, each coordinate of its optimal solution is an algebraic number. We study the degree of the minimal polynomials of these algebraic numbers. Geometrically,…

Optimization and Control · Mathematics 2008-09-09 Jiawang Nie , Kristian Ranestad , Bernd Sturmfels

One proves a far-reaching upper bound for the degree of a generically finite rational map between projective varieties over a base field of arbitrary characteristic. The bound is expressed as a product of certain degrees that appear…

Commutative Algebra · Mathematics 2021-01-29 M. Chardin , S. H. Hassanzadeh , A. Simis

In this paper we study the degrees of irrationality of hypersurfaces of large degree in a complex projective variety. We show that the maps computing the degrees of irrationality of these hypersurfaces factor through rational fibrations of…

Algebraic Geometry · Mathematics 2023-04-21 Jake Levinson , David Stapleton , Brooke Ullery

Given a minimal surface equipped with a generically finite map to an Abelian variety, we give an optimal bound on the canonical degree of a rational or an elliptic curve. As a corollary, we obtain the finiteness of rational and elliptic…

Algebraic Geometry · Mathematics 2008-08-12 Steven S. Y. Lu

It is still a challenging task of today to recognize the type of a given algebraic surface which is described only by its implicit representation. In~this paper we will investigate in more detail the case of canal surfaces that are often…

Symbolic Computation · Computer Science 2014-10-15 Jan Vršek , Miroslav Lávička

Let $F(x_1,...,x_n)$ be a form of degree $d\geq 2$, which produces a geometrically irreducible hypersurface in $\mathbb{P}^{n-1}$. This paper is concerned with the number of rational points on F=0 which have height at most $B$. Whenever…

Number Theory · Mathematics 2007-05-23 T. D. Browning , D. R. Heath-Brown

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 study arithmetic degree of a dominant rational self-map on a smooth projective variety over a function field of characteristic zero. We see that the notion of arithmetic degree and some related problems over function fields are…

Algebraic Geometry · Mathematics 2017-03-02 Yohsuke Matsuzawa , Kaoru Sano , Takahiro Shibata

The current paper discusses some new results about conformal polynomic surface parameterizations. A new theorem is proved: Given a conformal polynomic surface parameterization of any degree it must be harmonic on each component. As a first…

Differential Geometry · Mathematics 2012-05-28 David Pérez Fernández

PhD dissertation consists in three lines of investigation involving rational elliptic surfaces, namely 1) a study of conic bundles on these surfaces; 2) an investigation of the possible intersection numbers of two sections and 3) a theorem…

Algebraic Geometry · Mathematics 2023-02-14 Renato Dias Costa

In this paper we discuss the relationship between the moving planes of a rational parametric surface and the singular points on it. Firstly, the intersection multiplicity of several planar curves is introduced. Then we derive an equivalent…

Numerical Analysis · Mathematics 2010-01-14 Falai Chen , Xuhui Wang

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

The main purpose of this paper is to define dynamical degrees for rational maps over an algebraic closed field of characteristic zero and prove some basic properties (such as log-concavity) and give some applications. We also define…

Algebraic Geometry · Mathematics 2015-01-08 Tuyen Trung Truong

One of the most powerful ideas in the study and classification of algebraic varieties is the notion of a model: that is, to single out an object, in the appropriate isomorphism class, with nice properties. This survey aims to define and…

Algebraic Geometry · Mathematics 2025-11-11 Giacomo Graziani

Let X be a minimal complex surface of general type such that its image via the canonical map is a surface; we denote by d the degree of the canonical map. In this expository work, first of all we recall the known possibilities for the…

Algebraic Geometry · Mathematics 2021-03-03 Margarida Mendes Lopes , Rita Pardini

Building on work of Segre and Koll'ar on cubic hypersurfaces, we construct over imperfect fields of characteristic p\geq 3 particular hypersurfaces of degree p, which show that geometrically rational schemes that are regular and whose…

Algebraic Geometry · Mathematics 2020-02-24 Keiji Oguiso , Stefan Schröer

This paper shows that the multiplicity of the base points locus of a projective rational surface parametrization can be expressed as the degree of the content of a univariate resultant. As a consequence, we get a new proof of the degree…

Algebraic Geometry · Mathematics 2020-08-19 David A. Cox , Sonia Pérez-Díaz , J. Rafael Sendra

We study surjective (not necessarily regular) rational endomorphisms $f$ of smooth del Pezzo surfaces $X$. We prove that under certain natural non\,-\,degeneracy condition $f$ can have degree bigger than $1$ only when $(-K_X^2) > 5$. Some…

Algebraic Geometry · Mathematics 2025-06-03 Ilya Karzhemanov , Anna Lekontseva