On the fundamental groups of some open rational surfaces.
On the Normal Bundles of Smooth Rational Spaces Curves.
On the rationality of the moduli schemes of vector bundles on curves
On the Varieties Parametrizing Rational Space Curves with Fixed Normal Bundle.
On Unirationality of Supersingular Surfaces.
Points non factoriels des variétés de modules de faisceaux semi-stables sur une surface rationnelle.
Points rationnels et groupes fondamentaux : applications de la cohomologie -adique
Je présenterai des résultats de T. Ekedahl et H. Esnault sur les variétés projectives lisses sur un corps de caractéristique strictement positive, disons , dont deux points peuvent être liés par une chaîne de courbes rationnelles, par exemple faiblement unirationnelles, ou de Fano. Notamment : 1) sur un corps fini, de telles variétés ont un point rationnel, résultat qui généralise le théorème de Chevalley-Warning ; 2) sur un corps algébriquement clos, de telles variétés ont un groupe fondamental...
Problemi di razionalità ed unirazionalità in geometria algebrica
Il presente articolo è una versione allargata della omonima conferenza tenuta a Milano durante il XVII convegno nazionale UMI nel settembre 2003. L'articolo ha come abiettivo principale quello di presentare una introduzione, il più possibile elementare, ai problemi di razionalità/unirazionalità in geometria algebrica. Avendo come punto di riferimento l'esempio delle ipersuperfici dello spazio proiettivo complesso, in particolare le ipersuperfici cubiche, vengono presentati temi classici e problemi...
Quartic threefolds containing two skew double lines
Quelques propriétés arithmétiques des surfaces rationnelles (d'après Manin)
Quotient de la variété des points infiniment voisins d’ordre 9 sous l’action de
Rank-3 stable bundles on rational rundle ruled surfaces.
Rational connectedness and Galois covers of the projective line.
Rational connectivity and sections of families over curves
Rational Double Points on a Rational Surface.
Rationalité des Singularités Canoniques.
Rationality of Moduli Spaces of Stable Bundles.
Rationality of Moduli spaces of torsion free sheaves over rational surfaces.
Rationality of the moduli variety of curves of genus 3.
Rationality of the quotient of ℙ2 by finite group of automorphisms over arbitrary field of characteristic zero
Let be a field of characteristic zero and G be a finite group of automorphisms of projective plane over . Castelnuovo’s criterion implies that the quotient of projective plane by G is rational if the field is algebraically closed. In this paper we prove that is rational for an arbitrary field of characteristic zero.