English
Related papers

Related papers: Pencils on real curves

200 papers

We completely describe the Brill-Noether theory of pencils on general primitive covers of elliptic curves of any degree.

Algebraic Geometry · Mathematics 2024-01-26 Andreas Leopold Knutsen , Margherita Lelli-Chiesa

Under the assumption that the adjusted Brill-Noether number $\widetilde{\rho}$ is at least $-g$, we prove that the Brill-Noether loci in $\mathcal{M}_{g,n}$ of pointed curves carrying pencils with prescribed ramification at the marked…

Algebraic Geometry · Mathematics 2026-02-17 Andreas Leopold Knutsen , Sara Torelli

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 explicitly construct Brill--Noether general $K3$ surfaces of genus $4,6$ and $8$ having the maximal number of elliptic pencils of degrees $3, 4$ and $5$, respectively, and study their moduli spaces and moduli maps to the moduli space of…

Algebraic Geometry · Mathematics 2020-07-08 Michael Hoff , Andreas Leopold Knutsen

We study Brill-Noether existence on a finite graph using methods from polyhedral geometry and lattices. We start by formulating analogues of the Brill-Noether conjectures (both the existence and non-existence parts) for…

Combinatorics · Mathematics 2022-03-01 Madhusudan Manjunath

Given a triple covering $X$ of genus $g$ of a general (in the sense of Brill-Noether) curve $C$ of genus $h$, we show the existence of base-point-free pencils of degree $d$ which are not composed with the triple covering for any $d\ge…

alg-geom · Mathematics 2008-02-03 Takao Kato , Changho Keem , Akira Ohbuchi

We classify real families of minimal degree rational curves that cover an embedded rational surface. A corollary is that if the projective closure of a smooth surface is not biregular isomorphic to the projective closure of the unit-sphere,…

Algebraic Geometry · Mathematics 2021-03-09 Niels Lubbes

It goes back to Ahlfors that a real algebraic curve $C$ admits a separating morphism $f$ to the complex projective line if and only if the real part of the curve disconnects its complex part, i.e. the curve is \textit{separating}. The…

Algebraic Geometry · Mathematics 2023-10-31 Matilde Manzaroli

The paper gives topological as well as rigid isotopy classification of smooth irreducible algebraic curves in the real projective 3-space for the case when the degree of the curve is at most six and its genus is at most one.

Algebraic Geometry · Mathematics 2016-08-15 Grigory Mikhalkin , Stepan Orevkov

We consider smooth surfaces $S \subset \Pq$ containing a plane curve $P$ and prove some general result concerning the linear system $|H-P|$. We then look at regular surfaces lying on hypersurfaces of degree $s$ having a plane of…

Algebraic Geometry · Mathematics 2007-05-23 Ph. Ellia , C. Folegatti

We give necessary and sufficient topological conditions for a simple closed curve on a real rational surface to be approximable by smooth rational curves. We also study approximation by smooth rational curves with given complex…

Algebraic Geometry · Mathematics 2025-05-26 János Kollár , Frédéric Mangolte

We present an algorithm for computing curves and families of curves of prescribed degree and geometric genus on real rational surfaces.

Algebraic Geometry · Mathematics 2018-05-11 Niels Lubbes

The Brill-Noether Theorem gives necessary and sufficient conditions for the existence of a linear series. Here we consider a general n-fold, etale cyclic cover p of a curve C of genus g and investigate for which numbers r,d a linear series…

Algebraic Geometry · Mathematics 2018-11-16 Irene Schwarz

In this paper we examine the topology of Brill-Noether varieties associated to real trigonal curves. More precisely, we aim to count the connected components of the real locus of the varieties parametrizing linear systems of degree $d$ and…

Algebraic Geometry · Mathematics 2025-11-03 Turgay Akyar

Given a curve $C$ that is a degree $k$ cover $C \to \mathbb{P}^1$ totally ramified at two points $p$ and $q$, we can seek to understand the space of degree $d$ line bundles on $C$ with prescribed ramification at $p$ and $q$. The…

Algebraic Geometry · Mathematics 2026-04-30 Daksh Aggarwal

We complete our study of linear series on curves lying on an Enriques surface by showing that, with the exception of smooth plane quintics, there are no exceptional curves on Enriques surfaces, that is, curves for which the Clifford index…

Algebraic Geometry · Mathematics 2013-08-06 Andreas Leopold Knutsen , Angelo Felice Lopez

We develop a novel approach to the Brill-Noether theory of curves endowed with a degree k cover of the projective line via Bridgeland stability conditions on elliptic K3 surfaces. We first develop the Brill-Noether theory on elliptic K3…

Algebraic Geometry · Mathematics 2025-06-24 Gavril Farkas , Soheyla Feyzbakhsh , Andrés Rojas

We introduce and begin the topological study of real rational plane curves, all of whose inflection points are real. The existence of such curves is a corollary of results in the real Schubert calculus, and their study has consequences for…

Algebraic Geometry · Mathematics 2010-03-29 Viatcheslav Kharlamov , Frank Sottile

We define a signed count of real rational pseudo-holomorphic curves appearing in a one-parameter family of real Spin symplectic K3 surfaces. We show that this count is an invariant of the deformation class of the family. In the case of a…

Symplectic Geometry · Mathematics 2015-04-17 Crétois Rémi

We show that a general curve in an explicit class of what we call Du Val pointed curves satisfies the Brill-Noether Theorem for pointed curves. Furthermore, we prove that a generic pencil of Du Val pointed curves is disjoint from all…

Algebraic Geometry · Mathematics 2023-03-10 Gavril Farkas , Nicola Tarasca
‹ Prev 1 2 3 10 Next ›