On a Theorem of Castelnuovo, and the Equations Defining Space Curves.
On Bertini's theorem.
On b-function, spectrum and rational singularity.
On blowing down projective spaces in singular varieties.
On Castelnuovo's equivalence defect.
On complex projective surfaces with trigonal hyperplane sections.
On connected divisors.
On contractions of extremal rays of Fano manifolds.
On del Pezzo fibrations
On extremal rays of the higher dimensional varieties.
On generation of jets for vector bundles.
We introduce and study the k-jet ampleness and the k-jet spannedness for a vector bundle, E, on a projective manifold. We obtain different characterizations of projective space in terms of such positivity properties for E. We compare the 1-jet ampleness with different notions of very ampleness in the literature.
On generically polarized Gorenstein surfaces of sectional genus two.
On hypersurfaces in with fat points in general position.
On -very ampleness of tensor products of ample line bundles on abelian surfaces
On Kodaira energy and adjoint reduction of polarized threefolds.
On linearly normal strange curves
Here we prove a numerical bound implying that, except for smooth plane conics in characteristic 2, no complete linear system maps birationally a smooth curve into a projective space with a strange curve as image.
On Manifolds that Cannot be Ample Divisors.
On numerically effective log canonical divisors.
On Petri's Analysis of the Linear System of Quadrics through a Canonical Curve.
On polarized canonical Calabi-Yau threefolds.