Showing 2001Show all
3 papers · 1 filter
math.AG2001
Limites de fibres vectoriels dans
Nicolas Perrin
Let the smooth quadric in P^4 (the 4-dimensional projective space). In this note we completely describe the closure of the open set of vector bundles in ${\bf M}_{\m…
math.AG2001
Deformation de fibres vectoriels sur les varietes lisses de dimension trois
Nicolas Perrin
Let X be a smooth 3-fold and let E be a rank 2 torsion free sheaf. In the first part of this paper, we give some necessary conditions for the sheaf E to be limit of vector bundles.…
math.AG2001
Singular locus of rational ruled surfaces
Nicolas Perrin
We prove that the morphism that maps a rational ruled surface to its singular locus is genericaly injective modulo isomophism and duality. We also calculate the dimension and the d…