On the existence of supersingular curves of given genus.
On the existence of Weierstrass points whose first non-gaps are five.
On the extendability of elliptic surfaces of rank two and higher
We study threefolds having as hyperplane section a smooth surface with an elliptic fibration. We first give a general theorem about the possible embeddings of such surfaces with Picard number two. More precise results are then proved for Weierstrass fibrations, both of rank two and higher. In particular we prove that a Weierstrass fibration of rank two that is not a K3 surface is not hyperplane section of a locally complete intersection threefold and we give some conditions, for many embeddings...
On the extension of Nash functions.
On the ...-factor attached to motives.
On the Failure of Variational Torelli for Regular Elliptic Surfaces with a Section.
On the family of cyclic trigonal Riemann surfaces of genus 4 with several trigonal morphisms.
A closed Riemann surface which is a 3-sheeted regular covering of the Riemann sphere is called cyclic trigonal, and such a covering is called a cyclic trigonal morphism. Accola showed that if the genus is greater or equal than 5 the trigonal morphism is unique. Costa-Izquierdo-Ying found a family of cyclic trigonal Riemann surfaces of genus 4 with two trigonal morphisms. In this work we show that this family is the Riemann sphere without three points. We also prove that the Hurwitz space of pairs...
On the fiber of the compound of a real analytic function by a projection
Sia con una funzione analitica. Se il luogo critico di è compatto, esiste una fibrazione localmente triviale associata ai livelli . Supponiamo e sia la proiezione . Sotto una condizione sul luogo critico di esiste anche una fibrazione localmente triviale associata ai livelli di . Siano e le fibre rispettitive, e l'intervallo unità reale. Dimostriamo qui che è omeomorfa al prodotto . Nel caso di polinomi studiamo criteri effettivi. Diamo inoltre un'applicazione del risultato...
On the field of definition of superspecial polarized abelian varieties and type numbers
On the Finite Field Nullstellensatz for the intersection of two quadric hypersurfaces.
On the Finite Generation of Symbolic Blow-Ups.
On the finiteness of Pythagoras numbers of real meromorphic functions
We consider the 17th Hilbert Problem for global real analytic functions in a modified form that involves infinite sums of squares. Then we prove a local-global principle for a real global analytic function to be a sum of squares of global real meromorphic functions. We deduce that an affirmative solution to the 17th Hilbert Problem for global real analytic functions implies the finiteness of the Pythagoras number of the field of global real meromorphic functions, hence that of the field of real...
On the finiteness of rational curves on quintic threefolds
On the finiteness of for motives associated to modular forms.
On the finiteness theorem for rational maps on a variety of general type.
On the fixed part of certain linear systems on surfaces
On the formal inverse of polynomial endomorphisms
On the Fourier coefficients of modular forms. II.
On the Fundamental Group of a Unirational 3-Fold.
On the Fundamental Group of self-affine plane Tiles
Let be an expanding matrix, a set with elements and define via the set equation . If the two-dimensional Lebesgue measure of is positive we call a self-affine plane tile. In the present paper we are concerned with topological properties of . We show that the fundamental group of is either trivial or uncountable and provide criteria for the triviality as well as the uncountability of . Furthermore, we give a short proof of the fact that the closure of each component of is a locally...