On the classical characteristic linear series of plane curves with nodes and cuspidal points : two examples of Beniamino Segre
On the Clifford Index of a General (e+2)-gonal curve.
On the Complexity of the Projective Classification of Surfaces.
On the curves through an general point of a smooth surface in IP3.
On the Degree of the Discriminant Locus of a Smooth Sectional Surface of a (n + 2)-fold with Nonnegative Kodaria Dimension.
On the Difference of 4-Gonal Linear Systems on some Curves
Let C = (C, g^1/4 ) be a tetragonal curve. We consider the scrollar invariants e1 , e2 , e3 of g^1/4 . We prove that if W^1/4 (C) is a non-singular variety, then every g^1/4 ∈ W^1/4 (C) has the same scrollar invariants.
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 dimension of the adjoint linear system for threefolds
On the discriminant locus of an ample and spanned line bundle.
On the discriminant variety of a projective manifold.
On the fixed part of certain linear systems on surfaces
On the fundamental group of the complement of a divisor in a homogeneous space.
On the generalized theta divisor.
On the generic injectivity of the Gauss map in positive characteristic.
On the Geometrie Genera of Projective Curves.
On the geometry of algebraic curves having many real components.
We show that there is a large class of nonspecial effective divisors of relatively small degree on real algebraic curves having many real components i.e. on M-curves. We apply to 1. complete linear systems on M-curves containing divisors with entirely real support, and 2. morphisms of M-curves into P1.
On the homogeneous ideal of unreduced projective schemes.
On the Kodaira dimension of the moduli space of curves, II. The even-genus case.
On the k-regularity of some proyective manifolds.
The conjecture on the (degree-codimension + 1) - regularity of projective varieties is proved for smooth linearly normal polarized varieties (X,L) with L very ample, for low values of Delta(X,L) = degree-codimension-1. Results concerning the projective normality of some classes of special varieties including scrolls over curves of genus 2 and quadric fibrations over elliptic curves, are proved.
On the Lüroth Semigroup of curves lying on a smooth quadric.