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Given a fixed binary form $f(u,v)$ of degree $d$ over a field $k$, the associated \emph{Clifford algebra} is the $k$-algebra $C_f=k\{u,v\}/I$, where $I$ is the two-sided ideal generated by elements of the form $(\alpha u+\beta…

Rings and Algebras · Mathematics 2010-09-13 Emre Coskun

The new result is the unirationality of the moduli space of curves of genus 14. The method applies to lower genus.

Algebraic Geometry · Mathematics 2007-05-23 Alessandro Verra

We study the degree of the special cubic fourfolds in the Hilbert scheme of cubic fourfolds via a computation of the generating series of Heegner divisors of even lattice of signature (2, 20).

Algebraic Geometry · Mathematics 2015-07-29 Zhiyuan Li , Letao Zhang

We study the moduli spaces of rational curves on cubic hypersurfaces in characteristic $\neq2,3$. As a result, we prove that for every integer $d\geq1$ the Kontsevich moduli space of stable maps on a smooth cubic hypersurface $X$ of degree…

Algebraic Geometry · Mathematics 2026-04-30 Natsume Kitagawa

We present some families of cubic hypersurfaces in $\mathbb P^5 (\mathbb C)$ containing a plane whose associated quadric bundle does not have a rational section.

Algebraic Geometry · Mathematics 2016-06-30 Federica Galluzzi

We study the L-series of cubic fourfolds. Our main result is that, if X/C is a special cubic fourfold associated to some polarized K3 surface $S$, defined over a number field K such that S^[2](K) is not empty, then X has a model over K such…

Algebraic Geometry · Mathematics 2007-05-23 Klaus Hulek , Remke Kloosterman

Using the connection discovered by Hassett between the Noether-Lefschetz moduli space of special cubic fourfolds of discriminant 42 and the moduli space F_{22} of polarized K3 surfaces of genus 22, we show that the universal K3 surface over…

Algebraic Geometry · Mathematics 2021-09-09 Gavril Farkas , Alessandro Verra

We prove orientation results for evaluation maps of moduli spaces of rational stable maps to del Pezzo surfaces over a field, both in characteristic $0$ and in positive characteristic. These results and the theory of degree developed in a…

Algebraic Geometry · Mathematics 2026-03-27 Jesse Leo Kass , Marc Levine , Jake P. Solomon , Kirsten Wickelgren

A well-known principle of Mumford asserts that all moduli spaces of curves are varieties of general type, except a finite number of cases that occur for relatively small genus, when these varieties tend to be uniruled. In all known cases,…

Algebraic Geometry · Mathematics 2009-11-02 Gavril Farkas , Alessandro Verra

In this article, we provide an overview of a one-to-one correspondence between representations of the generalized Clifford algebra $C_f$ of a ternary cubic form $f$ and certain vector bundles (called Ulrich bundles) on a cubic surface $X$.…

Rings and Algebras · Mathematics 2011-07-11 Emre Coskun , Rajesh S. Kulkarni , Yusuf Mustopa

We construct explicit dominant, rational morphisms from projective bundles over rational varieties to relevant moduli spaces, showing their unirationality. These constructions work for $U_{r,d,g}$; for all ranks, degrees and genus $2\leq g…

Algebraic Geometry · Mathematics 2025-08-19 Shubham Saha

Let $X$ be a smooth irreducible projective curve of genus $g$ and gonality 4. We show that the canonical model of $X$ is contained in a uniquely defined surface, ruled by conics, whose geometry is deeply related to that of $X$. This surface…

Algebraic Geometry · Mathematics 2012-10-25 Michela Brundu , Gianni Sacchiero

For any standard quadric surface bundle over $\mathbb P^2$, we show that the locus of rational fibres is dense in the moduli space.

Algebraic Geometry · Mathematics 2023-11-22 Matthias Paulsen

The moduli space of cubic surfaces in complex projective space is known to be isomorphic to the quotient of the complex 4-ball by a certain arithmetic group. We apply Borcherds' techniques to construct automorphic forms for this group and…

Algebraic Geometry · Mathematics 2007-05-23 Daniel Allcock , Eberhard Freitag

We completely classify all plane curves of degree at most 30 with a unique cuspidal (locally unibranch) singular point and rational normalization in terms of the Newton pairs parameterizing the cusp. We distinguish between prime and…

Algebraic Geometry · Mathematics 2023-11-28 Kristin DeVleming , Nikita Singh

It is proved that a smooth rational surface in projective four-space, which is ruled by cubics or quartics has degree at most 12. It is also proved that a smooth rational surface in projective four-space which is the image of Fn by a linear…

Algebraic Geometry · Mathematics 2007-05-23 Philippe Ellia

We study the moduli space C^2 of unitary two-dimensional conformal field theories with central charge c=2. We construct all the 28 nonexceptional nonisolated irreducible components of C^2 that may be obtained by an orbifold procedure from…

High Energy Physics - Theory · Physics 2009-10-31 Sayipjamal Dulat , Katrin Wendland

A general linear determinantal quartic in $\mathbb{P}^4$ is nodal, non-$\mathbb{Q}$-factorial and rational. We show that the family $\mathcal{F}$ of such quartics also contains rational $\mathbb{Q}$-factorial quartics, and that a generic…

Algebraic Geometry · Mathematics 2025-08-26 Manuel Leal , César Lozano Huerta , Montserrat Vite

We show that a cubic fourfold F that is apolar to a Veronese surface has the property that its variety of power sums VSP(F,10) is singular along a K3 surface of genus 20. We prove that these cubics form a divisor in the moduli space of…

Algebraic Geometry · Mathematics 2017-02-14 Kristian Ranestad , Claire Voisin

The moduli space of stable real cubic surfaces is the quotient of real hyperbolic four-space by a discrete, nonarithmetic group. The volume of the moduli space is 37\pi^2/1080 in the metric of constant curvature -1. Each of the five…

Algebraic Geometry · Mathematics 2007-05-23 Daniel Allcock , James A. Carlson , Domingo Toledo