Second order theta divisors on Pryms
Sections des fibrés vectoriels sur une courbe
Self-adjoint determinantal representations of real plane curves.
Semistability of Frobenius direct images over curves
Let be a smooth projective curve of genus defined over an algebraically closed field of characteristic . Given a semistable vector bundle over , we show that its direct image under the Frobenius map of is again semistable. We deduce a numerical characterization of the stable rank- vector bundles , where is a line bundle over .
Sequences of rational torsions on abelian varieties.
Siegel modular forms vanishing on the moduli space.
Siegel's lemma, Padé approximations and jacobians
Singularities of -divisors in the jacobian
We consider the linear system of second order theta functions over the Jacobian of a non-hyperelliptic curve . A result by J.Fay says that a divisor contains the origin with multiplicity if and only if contains the surface . In this paper we generalize Fay’s result and some previous work by R.C.Gunning. More precisely, we describe the relationship between divisors containing with multiplicity , divisors containing the fourfold , and divisors singular along , using the third exterior...
Singularities of theta divisors and the geometry of
We study the codimension two locus in consisting of principally polarized abelian varieties whose theta divisor has a singularity that is not an ordinary double point. We compute the class for every . For , this turns out to be the locus of Jacobians with a vanishing theta-null. For , via the Prym map we show that has two components, both unirational, which we describe completely. We then determine the slope of the effective cone of and show that the component of the Andreotti-Mayer...
Some Curves in Abelian Varieties.
Some density results for curves with non-simple jacobians.
Some Results on the Mordell-Weil Group of the Jacobian of the Fermat Curve.
Some surfaces with maximal Picard number
For a smooth complex projective variety, the rank of the Néron-Severi group is bounded by the Hodge number . Varieties with have interesting properties, but are rather sparse, particularly in dimension . We discuss in this note a number of examples, in particular those constructed from curves with special Jacobians.
Sous-variétés spéciales des variétés de Prym
Special line bundles on curves with involution.
Spectral curves and the generalised theta divisor.
Sulla caratteristica della jacobiana dei sistemi lineari irriducibili di quadriche
Supersingular curves of genus two and class numbers
Sur certains sous-groupes de torsion de Joacobiennes de courbes hyperelliptiques de genre g ... 1.
Sur la démonstration de A. Weil du théorème de Torelli pour les courbes