Icosahedral Galois Extensions and Elliptic Curves.
We study the problem of constructing and enumerating, for any integers , number fields of degree whose ideal class groups have “large" -rank. Our technique relies fundamentally on Hilbert’s irreducibility theorem and results on integral points of bounded degree on curves.
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...
Nous comparons le comportement dans les -extensions du nombre de classes d’idéaux avec le comportement de l’indice du groupe des unités elliptiques de Rubin.
Under suitable hypotheses, we verify that the global root number of a motivic L-function is inductive (invariant under induction).
La méthode que Vojta a introduite dans sa preuve de la conjecture de Mordell et que Faltings a étendue pour prouver la conjecture de Lang sur les sous-variétés de variétés abéliennes repose sur une inégalité de hauteurs obtenue par approximation diophantienne. Nous montrons qu’une telle inégalité peut s’énoncer de manière très générale en dehors du contexte des groupes algébriques. Ce faisant, nous lui conférons également plus de souplesse, ce qui conduit à des applications nouvelles même sur les...
If E is an elliptic curve defined over a quadratic field K, and the j-invariant of E is not 0 or 1728, then has infinite rank. If E is an elliptic curve in Legendre form, y² = x(x-1)(x-λ), where ℚ(λ) is a cubic field, then has infinite rank. If λ ∈ K has a minimal polynomial P(x) of degree 4 and v² = P(u) is an elliptic curve of positive rank over ℚ, we prove that y² = x(x-1)(x-λ) has infinite rank over .
The aim of these notes is to provide an introduction to the subject of integral canonical models of Shimura varieties, and then to sketch a proof of the existence of such models for Shimura varieties of Hodge and, more generally, abelian type. For full details the reader is refered to [Ki 3].