Moduli reflexiver Garben und Flächen von kleinem Grad in IP4.
Non-obstructedness of Gorenstein Subschemes of Codimension 3 in P...
Notes on Varieties of Codimension 3 in Pn.
On a characterization of an abelian variety in the classification theory of algebraic varieties
On codimension-two subvarieties of hypersurfaces.
On Projective Varieties of Codimension 2.
On second fundamental forms of projective varieties.
On special projections of varieties: Epitome to a theorem of Beniamino Segre.
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 Defining Equations of Points in General Position in Pn.
On the existence of components of the Noether-Lefschetz Locus with given codiemsnion.
On the Hilbert scheme of Palatini threefolds.
On the Minimal Models of Complex Manifolds.
On the Noether-Lefschetz Theorem and Some Remarks on Codimension-two Cycles.
On the structure of linked 3-folds.
The structure of 3-folds in P6 which are generally linked via a complete intersection (f1,f2,f3) to 3-folds in P6 of degree d ≤ 5 is determined. We also give three new examples of smooth 3-folds in P6 of degree 11 and genus 9. These examples are obtained via liaison. The first two are 3-folds linked via a complete intersection (2,3,3) to 3-folds in P6 of degree 7: (i) the hyperquadric fibration over P1 and (ii) the scroll over P2. The third example is Pfaffian linked to a 3-dimensional quadric in...
Seshadri positive curves in a smooth projective -fold
A notion of positivity, called Seshadri ampleness, is introduced for a smooth curve in a polarized smooth projective -fold , whose motivation stems from some recent results concerning the gonality of space curves and the behaviour of stable bundles on under restriction to . This condition is stronger than the normality of the normal bundle and more general than being defined by a regular section of an ample rank- vector bundle. We then explore some of the properties of Seshadri-ample curves....
Smooth non-special surfaces of P4.
Some examples of Gorenstein liaison in codimension three.
Gorenstein liaison seems to be the natural notion to generalize to higher codimension the well-known results about liaison of varieties of codimension 2 in projective space. In this paper we study points in P3 and curves in P4 in an attempt to see how far typical codimension 2 results will extend. While the results are satisfactory for small degree, we find in each case examples where we cannot decide the outcome. This examples are candidates for counterexamples to the hoped-for extensions of codimension...
Specialization of Segre classes of singular algebraic varieties.
Subcanonicity of codimension two subvarieties.
We prove that smooth subvarieties of codimension two in Grassmannians of lines of dimension at least six are rationally numerically subcanonical. We prove the same result for smooth quadrics of dimension at least six under some extra condition. The method is quite easy, and only uses Serre s construction, Porteous formula, and Hodge index theorem.