The projectivity of the moduli space of stable curves, III: The line bundles on M..., and a proof of the projectivity of M... in characteristic 0.
The rationality of some moduli spaces of plane curves
The role of the Ellingsrud-Strømme construction in the classification of instantons
We review a construction of Ellingsrud-Strømme relating instantons of charge n on the ordinary projective space and theta-characteristics on a plane curve of degree n with some extra-structure.
The scheme of morphisms from an elliptic curve to a Grassmannian
The Second Homology Group of the Mapping Class Group of an Orientable Surface.
The Shafarevich-Tate Conjecture for Pencils of Elliptic Curves on K3 Surfaces.
The Singular Points on the Moduli Spaces for Smooth Curves.
The singularities of Yang-Mills connections for bundles on a surface.
The SL(2, C) - character varieties of torus knots.
The stability of certain classes of uni-ruled varieties
The stack quotient of a groupoid
The symplectic Kadomtsev-Petviashvili hierarchy and rational solutions of Painlevé VI
Equivalence is established between a special class of Painlevé VI equations parametrized by a conformal dimension , time dependent Euler top equations, isomonodromic deformations and three-dimensional Frobenius manifolds. The isomonodromic tau function and solutions of the Euler top equations are explicitly constructed in terms of Wronskian solutions of the 2-vector 1-constrained symplectic Kadomtsev-Petviashvili (CKP) hierarchy by means of Grassmannian formulation. These Wronskian solutions give...
The trivial locus of an analytic map germ
We prove: For a local analytic family of analytic space germs there is a largest subspace in such that the family is trivial over . Moreover the reduction of equals the germ of those points in for which is isomorphic to the special fibre .
The vanishing invariants in intersection homology of complex spaces
The variety of dual mock-Lie algebras
We classify all complex - and -dimensional dual mock-Lie algebras by the algebraic and geometric way. Also, we find all non-trivial complex -dimensional dual mock-Lie algebras.
Théorèmes de Lefschetz en cohomologie cohérente et en cohomologie étale
Topologie des fonctions régulières et cycles évanescents.
One has two notions of vanishing cycles: the Deligne's general notion and a concrete one used recently in the study of polynomial functions. We compare these two notions which gives us in particular a relative connectivity result. We finish with an example of vanishing cycle calculation which shows the difficulty of a good choice of compactification.
Topologisch triviale holomorphe Vektorbündel auf ... (...).
Topology of arrangements and position of singularities
This work contains an extended version of a course given in Arrangements in Pyrénées. School on hyperplane arrangements and related topics held at Pau (France) in June 2012. In the first part, we recall the computation of the fundamental group of the complement of a line arrangement. In the second part, we deal with characteristic varieties of line arrangements focusing on two aspects: the relationship with the position of the singular points (relative to projective curves of some prescribed degrees)...
Torelli theorem for stable curves
We study the Torelli morphism from the moduli space of stable curves to the moduli space of principally polarized stable semi-abelic pairs. We give two characterizations of its fibers, describe its injectivity locus, and give a sharp upper bound on the cardinality of finite fibers. We also bound the dimension of infinite fibers.