Improved bounds on the number of low-degree points on certain curves
Improved upper bounds for the number of points on curves over finite fields
We give new arguments that improve the known upper bounds on the maximal number of rational points of a curve of genus over a finite field , for a number of pairs . Given a pair and an integer , we determine the possible zeta functions of genus- curves over with points, and then deduce properties of the curves from their zeta functions. In many cases we can show that a genus- curve over with points must have a low-degree map to another curve over , and often this is enough to...
Improvement of Grauert-Riemenschneider's theorem for a normal surface
Let be a desingularization of a normal surface . The group Pic is provided with an order relation , defined by . for any effective exceptional divisor . Comparing to the usual order relation we define the ceiling of which is an exceptional divisor. This notion allows us to improve the usual vanishing theorem and we deduce from it a numerical criterion for rationality and a genus formula for a curve on a normal surface; the difficulty lies in the case of a Weil divisor which is not a Cartier...
Incollamento di punti chiusi e gruppo fondamentale algebrico e topologico
Indecomposable Cohen-Macaulay modules and irreducible maps
Indecomposable parabolic bundles
We study the possible dimension vectors of indecomposable parabolic bundles on the projective line, and use our answer to solve the problem of characterizing those collections of conjugacy classes of n×n matrices for which one can find matrices in their closures whose product is equal to the identity matrix. Both answers depend on the root system of a Kac-Moody Lie algebra. Our proofs use Ringel’s theory of tubular algebras, work of Mihai on the existence of logarithmic connections, the Riemann-Hilbert...
Indecomposable projective modules on affine domains
Indecomposable Quadratic Bundles of rank 4n over the Real Affine Plane.
Indépendance algébrique de nombres transcendants: quelques résultats récents.
Indépendance par rapport à des polynômes caractéristiques des endomorphismes de Frobenius de la cohomologie -adique
Index invariants of orbit spaces.
Indice de Clifford des intersections complètes de l'espace
Indice d’un opérateur différentiel linéaire -adique d’ordre et cohomologie -adiques
Indice d'un opérateur différentiel linéaire p-adique d'ordre 1 et cohomologie p-adique
Indice d’un opérateur différentiel -adique IV. Cas des systèmes. Mesure de l’irrégularité dans un disque
Nous désirons savoir si l’opérateur différentiel d’ordre , où est une matrice à coefficients rationnels, a un indice dans l’espace des fonctions analytiques dans une boule; dans le cas où cet indice existe nous voulons aussi le calculer. Dans le cas où nous montrons l’existence d’un indice (si l’exposant de l’opérateur n’est pas Liouville -adique) et nous montrons comment calculer cet indice. De même nous savons montrer l’existence d’un indice et comment calculer cet indice lorsque le système...
Indices of 1-forms and Newton polyhedra.
A formula of Matsuo Oka (1990) expresses the Milnor number of a germ of a complex analytic map with a generic principal part in terms of the Newton polyhedra of the components of the map. In this paper this formula is generalized to the case of the index of a 1-form on a local complete intersection singularity (Theorem 1.10, Corollaries 1.11, 4.1). In particular, the Newton polyhedron of a 1-form is defined (Definition 1.6). This also simplifies the Oka formula in some particular cases (Propositions...
Indices of double coverings of genus 1 over -adic fields
Induced -modules and differential complexes
Induced Modules and Extensions of Representations.