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In this paper, we study moduli spaces of sextic curves with simple singularities. Through period maps of K3 surfaces with ADE singularities, we prove that such moduli spaces admit algebraic open embeddings into arithmetic quotients of type…

Algebraic Geometry · Mathematics 2025-12-19 Chenglong Yu , Zhiwei Zheng , Yiming Zhong

We classify the smooth projective symmetric G-varieties with Picard number one (and G semisimple). Moreover we prove a criterion for the smoothness of the simple (normal) symmetric varieties whose closed orbit is complete. In particular we…

Algebraic Geometry · Mathematics 2008-09-26 Alessandro Ruzzi

The surfaces considered are real, rational and have a unique smooth real $(-2)$-curve. Their canonical class $K$ is strictly negative on any other irreducible curve in the surface and $K^2>0$. For surfaces satisfying these assumptions, we…

Algebraic Geometry · Mathematics 2018-05-17 Ilia Itenberg , Viatcheslav Kharlamov , Eugenii Shustin

Let $\mathbb{Q}_3$ be the complex 3-quadric endowed with its standard complex conformal structure. We study the complex conformal geometry of isotropic curves in $\mathbb{Q}_3$. By an isotropic curve we mean a nonconstant holomorphic map…

Differential Geometry · Mathematics 2021-10-07 Emilio Musso , Lorenzo Nicolodi

This paper investigates the geometry of a smooth canonically polarized surface $X$ defined over an algebraically closed field of characteristic $p>0$ in the case when the automorphism scheme of $X$ is not smooth. This is a situation that…

Algebraic Geometry · Mathematics 2015-07-01 Nikolaos Tziolas

A finite subgroup of the conformal group SL(2,C) can be related to invariant polynomials on a hypersurface in C^3. The latter then carries a simple singularity, which resolves by a finite iteration of basic cycles of deprojections. The…

General Relativity and Quantum Cosmology · Physics 2010-11-01 M. Rainer

We utilise the two principles of decoupling introduced in [arXiv:2407.16108] to prove decoupling for two types of surfaces exhibiting radial symmetry. The first type are surfaces of revolution in $\mathbb R^n$ generated by smooth surfaces…

Classical Analysis and ODEs · Mathematics 2025-07-08 Jianhui Li , Tongou Yang

We show that each connected component of the moduli space of smooth real binary quintics is isomorphic to an open subset of an arithmetic quotient of the real hyperbolic plane. Moreover, our main result says that the induced metric on this…

Algebraic Geometry · Mathematics 2026-01-14 Olivier de Gaay Fortman

We study the deformations of the minimally elliptic surface singularity $N_{16}$. A standard argument reduces the study of the deformations of $N_{16}$ to the study of the moduli space of pairs $(C,L)$ consisting of a plane quintic curve…

Algebraic Geometry · Mathematics 2011-09-28 Radu Laza

For each integer $D\ge3$, we give a sharp bound on the number of lines contained in a smooth complex $2D$-polarized $K3$-surface in $\mathbb{P}^{D+1}$. In the two most interesting cases of sextics in $\mathbb{P}^4$ and octics in…

Algebraic Geometry · Mathematics 2019-09-13 Alex Degtyarev

One of the simplest examples of a smooth, non degenerate surface in P^4 is the quintic elliptic scroll. It can be constructed from an elliptic normal curve E by joining every point on E with the translation of this point by a non-zero…

Algebraic Geometry · Mathematics 2007-05-23 C. Ciliberto , K. Hulek

We develop a geometric approach to the study of plane sextics with a triple singular point. As an application, we give an explicit geometric description of all irreducible maximal sextics with a type $\bold E_7$ singular point and compute…

Algebraic Geometry · Mathematics 2014-11-11 Alex Degtyarev

We show that the classical Fermat quartic has exactly three smooth spatial models. As a generalization, we give a classification of smooth spatial (as well as some other) models of singular $K3$-surfaces of small discriminant. As a…

Algebraic Geometry · Mathematics 2019-09-13 Alex Degtyarev

From a topological viewpoint, a rational curve in the real projective plane is generically a smoothly immersed circle and a finite collection of isolated points. We give an isotopy classification of generic rational quintics in…

Algebraic Geometry · Mathematics 2019-10-14 Ilia Itenberg , Grigory Mikhalkin , Johannes Rau

We discover a simple construction of a four-dimensional family of smooth surfaces of general type with $p_g(S)=q(S)=0$, $K^2_S=3$ with cyclic fundamental group $C_{14}$. We use a degeneration of the surfaces in this family to find…

Algebraic Geometry · Mathematics 2020-04-23 Lev Borisov , Enrico Fatighenti

In this paper we finish the topological classification of real algebraic surfaces of Kodaira dimension zero and we make a step towards the Enriques classification of real algebraic surfaces, by describing in detail the structure of the…

Algebraic Geometry · Mathematics 2007-05-23 Fabrizio Catanese , Paola Frediani

We study the deformation theory of rational curves on primitive symplectic varieties and show that if the rational curves cover a divisor, then, as in the smooth case, they deform along their Hodge locus in the universal locally trivial…

Algebraic Geometry · Mathematics 2021-03-31 Christian Lehn , Giovanni Mongardi , Gianluca Pacienza

In the open problem of classification of rational cuspidal plane curves it is essential to find good necessary conditions on the type of singularities of a curve C in order C to exit. Motivated by the study of the Seiberg-Witten invariant…

Algebraic Geometry · Mathematics 2007-05-23 J. Fernández de Bobadilla , I. Luengo-Velasco , A. Melle-Hernández , A. Némethi

We study real trigonal curves and elliptic surfaces of type $\I$ (over a base of an arbitrary genus) and their fiberwise equivariant deformations. The principal tool is a real version of Grothendieck's \emph{dessins d'enfants}. We give a…

Algebraic Geometry · Mathematics 2014-06-06 Alex Degtyarev , Ilia Itenberg , Victor Zvonilov

We study the pencils of minimal degree on the smooth curves lying on a K3 surface X which carries a fixed-point free involution. Generically, the gonality of these curves is totally governed by the genus 1 fibrations of X

Algebraic Geometry · Mathematics 2019-07-30 Marco Ramponi