Caractérisations de l'espace projectif (conjectures de Hartshorne et de Frankel)
Classical Godeaux Surface in Characteristic P.
Classical projective geometry and arithmetic groups.
Classification of Buchsbaum subvarieties of codimension 2 in projective space.
Classification of Maximal Rank Curves in the Liasion Class Ln.
Classification of smooth congruences of low degree.
Completion of the variety of conics with respect to contract conditions I
Concerning the existence of nice components in the Hilbert scheme of curves in ...n for n = 4 and 5.
Configuration space of 8 points on the projective line and a 5-dimensional Picard modular group
Configurations of lines and general hyperplane sections.
Congruences of lines with one-dimensional focal locus.
Construction of space curves with good properties.
Courbes generales de p...
Courbes lisses qui ne sont pas intersection de 3 surfaces dans l'espace projectif
Courbes passant par points généraux de
Courbes rationnelles et droites en position générale
On montre que la réunion générale d’une courbe rationnelle avec des droites dans est de rang maximum.
Curves in P2(C) with 1-dimensional symmetry.
In a previous paper we showed that the existence of a 1-parameter symmetry group of a hypersurface X in projective space was equivalent to failure of versality of a certain unfolding. Here we study in detail (reduced) plane curves of degree d ≥ 3, excluding the trivial case of cones. We enumerate all possible group actions -these have to be either semisimple or unipotent- for any degree d. A 2-parameter group can only occur if d = 3. Explicit lists of singularities of the corresponding curves are...
Curves on surfaces of degree 2r-... in Pr.