On Singularities of the Curves Belonging to some linear system in P2.
On special projections of varieties: Epitome to a theorem of Beniamino Segre.
On spinor varieties and their secants.
On the adjoint system to a very ample divisor on a surface and connected inequalities
Si caratterizzano alcune classi di superfici in relazione all’indice di autointersezione dell'aggiunto ad un divisore molto ampio.
On the adjoint system to a very ample divisor on a surface and connected inequalities
Siano: una superficie algebrica proiettiva complessa non singolare, un divisore canonico ed un divisore molto ampio su . Questo lavoro ha per oggetto lo studio dell'indice di autointersezione . Si dimostra, innanzitutto, la disuguaglianza , nell'ipotesi che la superficie ottenuta immergendo mediante il sistema lineare completo non sia uno scroll. Questa disuguaglianza è connessa con alcuni risultati di Sommese e Van de Ven sulla generazione del fascio . La dimostrazione della (I)...
On the adjunction theoretic classification of projective varieties.
On the Affine Bezout Inequaltiy.
On the arithmetic of certain intersections of two quadrics.
On the Burkhardt quartic.
On the class of some projective varieties.
Some inequalities between the class and the degree of a smooth complex projective manifold are given. Application to the case of low sectional genus are supplied.
On the classical characteristic linear series of plane curves with nodes and cuspidal points : two examples of Beniamino Segre
On the Complexity of the Projective Classification of Surfaces.
On the curves through an general point of a smooth surface in IP3.
On the diffeomorphic type of the complement to a line arrangement in a projective plane
We show that the diffeomorphic type of the complement to a line arrangement in a complex projective plane P 2 depends only on the graph of line intersections if no line in the arrangement contains more than two points in which at least two lines intersect. This result also holds for some special arrangements which do not satisfy this property. However it is not true in general, see [Rybnikov G., On the fundamental group of the complement of a complex hyperplane arrangement, Funct. Anal. Appl., 2011,...
On the dimension of secant varieties
In this paper we generalize Zak’s theorems on tangencies and on linear normality as well as Zak’s definition and classification of Severi varieties. In particular we find sharp lower bounds for the dimension of higher secant varieties of a given variety under suitable regularity assumptions on , and we classify varieties for which the bound is attained.
On the dual variety in characteristic 2
On the enumerative geometry of real algebraic curves having many real branches.
On the existence of components of the Noether-Lefschetz Locus with given codiemsnion.
On the existence of curves with maximal rank in Pn.
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...