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Related papers: A note related to Severi's finiteness theorem

200 papers

We address the problem of the maximal finite number of real points of a real algebraic curve (of a given degree and, sometimes, genus) in the projective plane. We improve the known upper and lower bounds and construct close to optimal…

Algebraic Geometry · Mathematics 2019-09-13 Erwan Brugallé , Alex Degtyarev , Ilia Itenberg , Frédéric Mangolte

We prove several finiteness theorems for the normal bundles to souls in nonnegatively curved manifolds. More generally, we obtain finiteness results for open Riemannian manifolds whose topology is concentrated on compact domains of…

Differential Geometry · Mathematics 2007-05-23 Igor Belegradek , Vitali Kapovitch

We prove a semiample generalization of Poonen's Bertini Theorem over a finite field that implies the existence of smooth sections for wide new classes of divisors. The probability of smoothness is computed as a product of local…

Algebraic Geometry · Mathematics 2015-11-03 Daniel Erman , Melanie Matchett Wood

In this paper we focus on the problem of computing the number of moduli of the so called Severi varieties (denoted by V(|D|, \delta)), which parametrize universal families of irreducible, \delta-nodal curves in a complete linear system |D|,…

Algebraic Geometry · Mathematics 2007-05-23 F. Flamini

The classical Severi degree counts the number of algebraic curves of fixed genus and class passing through points in a surface. We express the Severi degrees of CP1 x CP1 as matrix elements of the exponential of a single operator M on Fock…

Algebraic Geometry · Mathematics 2017-05-04 Yaim Cooper , Rahul Pandharipande

We prove results generalizing the classical Riemann Singularity Theorem to the case of integral, singular curves. The main result is a computation of the multiplicity of the theta divisor of an integral, nodal curve at an arbitrary point.…

Algebraic Geometry · Mathematics 2015-03-13 Sebastian Casalaina-Martin , Jesse Leo Kass

The Severi degree is the degree of the Severi variety parametrizing plane curves of degree d with delta nodes. Recently, G\"ottsche and Shende gave two refinements of Severi degrees, polynomials in a variable y, which are conjecturally…

Algebraic Geometry · Mathematics 2019-02-20 Florian Block , Lothar Göttsche

We study hyperbolic curves and their Jacobians over finite fields in the context of anabelian geometry.

Algebraic Geometry · Mathematics 2008-02-27 Fedor Bogomolov , Mikhail Korotiaev , Yuri Tschinkel

Severi varieties and Brill-Noether theory of curves on K3 surfaces are well understood. Yet, quite little is known for curves on abelian surfaces. Given a general abelian surface $S$ with polarization $L$ of type $(1,n)$, we prove…

Algebraic Geometry · Mathematics 2015-03-25 Andreas Leopold Knutsen , Margherita Lelli-Chiesa , Giovanni Mongardi

The main purpose of this note is to establish the continuity of seminorms on finite-dimensional vector spaces over the real or complex numbers.

Rings and Algebras · Mathematics 2016-12-13 Moshe Goldberg

We proved that the general members of Severi varieties on an Atiyah ruled surface over a general elliptic curve have nodes and ordinary triple points as singularities.

Algebraic Geometry · Mathematics 2026-05-27 Xiaotian Chang , Xi Chen , Adrian Zahariuc

We prove Bertini type theorems and give some applications of them. The applications are in the context of Lefschetz theorem for Nori fundamental group for normal varieties as well as for geometric formal orbifolds. In another application,…

Algebraic Geometry · Mathematics 2024-04-22 Indranil Biswas , Manish Kumar , A. J. Parameswaran

We enumerate the singular algebraic curves in a complete linear system on a smooth projective surface. The system must be suitably ample in a rather precise sense. The curves may have up to eight nodes, or a triple point of a given type and…

Algebraic Geometry · Mathematics 2007-05-23 Steven Kleiman , Ragni Piene

We consider the class of curves of finite total curvature, as introduced by Milnor. This is a natural class for variational problems and geometric knot theory, and since it includes both smooth and polygonal curves, its study shows us…

Geometric Topology · Mathematics 2007-10-24 John M Sullivan

We give sharp lower bounds for the degree of the syzygies involving the partial derivatives of a homogeneous polynomial defining an even dimensional nodal hypersurface. This implies the validity of formulas due to M. Saito, L. Wotzlaw and…

Algebraic Geometry · Mathematics 2019-09-17 Alexandru Dimca

The geometry of algebraic curves over finite fields is a rich area of research. In previous work, the authors investigated a particular aspect of the geometry over finite fields of the classical unit circle, namely how the number of…

Number Theory · Mathematics 2018-03-01 Vagn Lundsgaard Hansen , Andreas Aabrandt

Let $(S,L)$ be a general primitively polarized $K3$ surface of genus $g$. For every $0\leq \delta \leq g$ we consider the Severi variety parametrizing integral curves in $|L|$ with exactly $\delta$ nodes as singularities. We prove that its…

Algebraic Geometry · Mathematics 2023-08-01 Andrea Bruno , Margherita Lelli-Chiesa

We prove effective upper bounds on the global sections of nef line bundles of small generic degree over a fibered surface over a field of any characteristic. It can be viewed as a relative version of the classical Noether inequality for…

Algebraic Geometry · Mathematics 2013-04-24 Xinyi Yuan , Tong Zhang

We give two generalizations of the Clifford theorem to algebraic surfaces. As an application, we obtain some bounds for the number of moduli of surfaces of general type.

Algebraic Geometry · Mathematics 2013-01-08 Hao Sun

The purpose of this paper is two-fold. We first prove a series of results, concerned with the notion of Zariski multiplicity, mainly for non-singular algebraic curves. These results are required in the paper "A Theory of Branches for…

Algebraic Geometry · Mathematics 2007-05-23 Tristram de Piro