Tableaux de Young et fonctions de Schur-Littlewood
Tame homomorphisms of polytopal rings.
Tangent cones at Gorenstein singularities
Tangent star cones.
Tangentes limites, cône de Whitney et régularité par intersection
Nous caractérisons, en terme de dimension (topologique et de Hausdorff) des fibres des espaces de limites de tangents et du cône de Whitney, les conditions de régularité et sur une stratification . Nous précisons ces résultats lorsque les espaces qui interviennent ne sont pas fractals, en particulier lorsque la stratification est sous-analytique.
Tate duality and wild ramification.
Techniques de construction et théorèmes d'existence en géométrie algébrique III : préschémas quotients
Tensor complexes: multilinear free resolutions constructed from higher tensors
The most fundamental complexes of free modules over a commutative ring are the Koszul complex, which is constructed from a vector (i.e., a 1-tensor), and the Eagon-Northcott and Buchsbaum-Rim complexes, which are constructed from a matrix (i.e., a 2-tensor). The subject of this paper is a multilinear analogue of these complexes, which we construct from an arbitrary higher tensor. Our construction provides detailed new examples of minimal free resolutions, as well as a unifying view on a wide variety...
Teoria dei fasci e trasformazioni integrali per -moduli tra varietà di Grassmann
The automorphism group of linear sections of the Grassmannians .
The boundedness of singular subvarieties of not of a general type and with low codimension
Sia una varietà irriducibile -dimensionale localmente Cohen-Macaulay, -Gorenstein e non di tipo generale; assumiamo , e . In questo lavoro dimostriamo che e quindi che l'insieme di tutte queste varietà è parametrizzato da un insieme finito di varietà algebriche.
The Brauer-Manin obstructions for homogeneous spaces with connected or abelian stabilizer.
The Cayley Trick, lifting subdivisions and the Bohne-Dress theorem on zonotopal tilings
In 1994, Sturmfels gave a polyhedral version of the Cayley Trick of elimination theory: he established an order-preserving bijection between the posets of coherent mixed subdivisions of a Minkowski sum of point configurations and of coherent polyhedral subdivisions of the associated Cayley embedding . In this paper we extend this correspondence in a natural way to cover also non-coherent subdivisions. As an application, we show that the Cayley Trick combined with results of Santos on subdivisions...
The classification of weighted projective spaces
We obtain two classifications of weighted projective spaces: up to hoeomorphism and up to homotopy equivalence. We show that the former coincides with Al Amrani's classification up to isomorphism of algebraic varieties, and deduce the latter by proving that the Mislin genus of any weighted projective space is rigid.
The cohomology ring of polygon spaces
We compute the integer cohomology rings of the “polygon spaces”introduced in [F. Kirwan, Cohomology rings of moduli spaces of vector bundles over Riemann surfaces, J. Amer. Math. Soc., 5 (1992), 853-906] and [M. Kapovich & J. Millson, the symplectic geometry of polygons in Euclidean space, J. of Diff. Geometry, 44 (1996), 479-513]. This is done by embedding them in certain toric varieties; the restriction map on cohomology is surjective and we calculate its kernel using ideas from the theory...
The curve , is not set-theoretic complete intersection of two quartic surfaces
The decomposition and specialization of algebraic families of vector bundles
The defect of weak approximation for homogeneous spaces
The Denef-Loeser series for toric surface singularities.
Let H denote the set of formal ares going through a singular point of an algebraic variety V defined over an algebraically closed field k of charactcristic zcro. In the late sixties, J, Nash has observed that for any nonnegative integer s, the set js(H) of s-jets of ares in H is a constructible subset of some affine space. Recently (1999), J. Denef and F. Loeser have proved that the Poincaré series associated with the image of js(H) in some suitable localization of the Grothendieck ring of algebraic...
The determinant line bundle over moduli spaces of instantons on abelian surfaces.