0000000000756186
AUTHOR
Alessandra Sarti
On the Neron-Severi group of surfaces with many lines
For a binary quartic form $\phi$ without multiple factors, we classify the quartic K3 surfaces $\phi(x,y)=\phi(z,t)$ whose Neron-Severi group is (rationally) generated by lines. For generic binary forms $\phi$, $\psi$ of prime degree without multiple factors, we prove that the Neron-Severi group of the surface $\phi(x,y)=\psi(z,t)$ is rationally generated by lines.
Symmetric Surfaces with Many Singularities
Abstract Let G ⊂ SO(4) denote a finite subgroup containing the Heisenberg group. In this paper we classify all such groups, we find the dimension of the spaces of G-invariant polynomials and we give equations for the generators whenever the space has dimension two. Then we complete the study of the corresponding G-invariant pencils of surfaces in ℙ3 which we started in Sarti [Sarti, A. (2000). Pencils of symmetric surfaces in ℙ3(C). J. Algebra 246:429–452]. It turns out that we have five more pencils, two of them containing surfaces with nodes.
Eine K3-Fläche - oder: Eine Anmerkung zum Umschlag
K3-Flachen bekamen ihren Namen im 20. Jahrhundert vom franzosischen Mathematiker Andre Weil; er schreibt: Im zweiten Teil meines Berichts geht es um kahlersche Varietaten, K3 genannt, zu Ehren von Kummer, Kodaira, Kahler und des Berges K2 im Kaschmir-Gebirge. Dies sind komplexe Flachen, deren exakte Definition zwar recht technisch ist, von denen man jedoch einen guten Eindruck bekommt, wenn man Flachen vom Grad 4 im komplexen Dreiraum betrachtet, die namlich grostenteils K3Flachen sind.
Projective models of K3 surfaces with an even set
The aim of this paper is to describe algebraic K3 surfaces with an even set of rational curves or of nodes. Their minimal possible Picard number is nine. We completely classify these K3 surfaces and after a carefull analysis of the divisors contained in the Picard lattice we study their projective models, giving necessary and sufficient conditions to have an even set. Moreover we investigate their relation with K3 surfaces with a Nikulin involution.
Symplectic automorphisms of prime order on K3 surfaces
The aim of this paper is to study algebraic K3 surfaces (defined over the complex number field) with a symplectic automorphism of prime order. In particular we consider the action of the automorphism on the second cohomology with integer coefficients. We determine the invariant sublattice and its perpendicular complement, and show that the latter coincides with the Coxeter-Todd lattice in the case of automorphism of order three. We also compute many explicit examples, with particular attention to elliptic fibrations.
Transcendental lattices of some K 3-surfaces
In a previous paper, (S2), we described six families of K3-surfaces with Picard- number 19, and we identified surfaces with Picard-number 20. In these notes we classify some of the surfaces by computing their transcendental lattices. Moreover we show that the surfaces with Picard-number 19 are birational to a Kummer surface which is the quotient of a non-product type abelian surface by an involution.