A vanishing theorem on arithmetic surfaces.
Abelian extensions of an absolutely unramified local field with general residue field.
Abelian splitting of division algebras of prime degrees.
Abelian Varieties Attached to Polarized K3-Surfaces.
About -bundles over elliptic curves
Let be a complex algebraic group, simple and simply connected, a maximal torus and the Weyl group. One shows that the coarse moduli space parametrizing -equivalence classes of semistable -bundles over an elliptic curve is isomorphic to . By a result of Looijenga, this shows that is a weighted projective space.
About restricting 2-bundles on IP3 to planes.
About the Euler-Poincaré characteristic of semi-algebraic sets defined with two inequalities.
We express the Euler-Poincaré characteristic of a semi-algebraic set, which is the intersection of a non-singular complete intersection with two polynomial inequalities, in terms of the signatures of appropriate bilinear symmetric forms.
Absolute cohomological purity
ACM bundles on general hypersurfaces in P5 of low degree.
In this paper we show that on a general hypersurface of degree r = 3,4,5,6 in P5 a rank 2 vector bundle ε splits if and only if h1ε(n) = h2ε(n) = 0 for all n ∈ Z. Similar results for r = 1,2 were obtained in [15], [16] and [2].
ACM bundles, quintic threefolds and counting problems
We review some facts about rank two arithmetically Cohen-Macaulay bundles on quintic threefolds. In particular, we separate them into seventeen natural classes, only fourteen of which can appear on a general quintic. We discuss some enumerative problems arising from these.
Addendum : Propriétés de descente des variétés à fibré cotangent ample
Addendum to the paper : “Formal cohomology, analytic cohomology and non-algebraic manifolds”
Adeles and differential forms.
Adjoint bundles of ample and spanned vector bundles on algebraic surfaces.
Adjunction properties of polarized surfaces via Reider's method.
Affine braid group actions on derived categories of Springer resolutions
In this paper we construct and study an action of the affine braid group associated with a semi-simple algebraic group on derived categories of coherent sheaves on various varieties related to the Springer resolution of the nilpotent cone. In particular, we describe explicitly the action of the Artin braid group. This action is a “categorical version” of Kazhdan-Lusztig-Ginzburg’s construction of the affine Hecke algebra, and is used in particular by the first author and I. Mirković in the course...
Affine varieties dominated by C2.
Albanese varieties with modulus and Hodge theory
Let be a proper smooth variety over a field of characteristic and an effective divisor on with multiplicity. We introduce a generalized Albanese variety Alb of of modulus , as higher dimensional analogue of the generalized Jacobian with modulus of Rosenlicht-Serre. Our construction is algebraic. For we give a Hodge theoretic description.
Algebraic and analytic cohomology of quasiprojective varieties.
Algebraic and symplectic Gromov-Witten invariants coincide
For a complex projective manifold Gromov-Witten invariants can be constructed either algebraically or symplectically. Using the versions of Gromov-Witten theory by Behrend and Fantechi on the algebraic side and by the author on the symplectic side, we prove that both points of view are equivalent