4 papers · 1 filter
Sur les conditions d'existence des faisceaux semi-stables sur les courbes multiples primitives
Jean-Marc Drezet
We give sufficient conditions for the (semi-)stability of torsion free sheaves on a primitive multiple curve. These conditions are used to prove that some moduli spaces of stable s…
Faisceaux sans torsion et faisceaux quasi localement libres sur les courbes multiples primitives
Jean-Marc Drezet
This paper is devoted to the study of some coherent sheaves on non reduced curves that can be locally embedded in smooth surfaces. If Y is such a curve then there is a filtration b…
Deformations des extensions larges de faisceaux
Jean-Marc Drezet
Let X be a projective smooth irreducible polarized variety over the field of complex numbers. Typical examples of wide extensions are vector bundles E that have a subsheaf F whose…
Géométrie orthogonale non symétrique et congruences quadratiques
J. -M. Drézet
In this paper, some particular rational maps P_n ---> P_n+1, called quadratic congruences, are studied. They appear in the theory of exceptional vector bundles on projective spaces…