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Sur le rang des jacobiennes sur un corps de fonctions

Marc Hindry, Amílcar Pacheco (2005)

Bulletin de la Société Mathématique de France

Soit f : 𝒳 C une surface projective fibrée au-dessus d’une courbe et définie sur un corps de nombres k . Nous donnons une interprétation du rang du groupe de Mordell-Weil sur k ( C ) de la jacobienne de la fibre générique (modulo la partie constante) en termes de moyenne des traces de Frobenius sur les fibres de f . L’énoncé fournit une réinterprétation de la conjecture de Tate pour la surface 𝒳 et généralise des résultats de Nagao, Rosen-Silverman et Wazir.

The Brauer group and the Brauer–Manin set of products of varieties

Alexei N. Skorobogatov, Yuri G. Zahrin (2014)

Journal of the European Mathematical Society

Let X and Y be smooth and projective varieties over a field k finitely generated over Q , and let X ¯ and Y ¯ be the varieties over an algebraic closure of k obtained from X and Y , respectively, by extension of the ground field. We show that the Galois invariant subgroup of Br ( X ¯ ) Br( Y ¯ ) has finite index in the Galois invariant subgroup of Br ( X ¯ × Y ¯ ) . This implies that the cokernel of the natural map Br ( X ) Br ( Y ) Br ( X × Y ) is finite when k is a number field. In this case we prove that the Brauer–Manin set of the product of...

The p -part of Tate-Shafarevich groups of elliptic curves can be arbitrarily large

Remke Kloosterman (2005)

Journal de Théorie des Nombres de Bordeaux

In this paper we show that for every prime p 5 the dimension of the p -torsion in the Tate-Shafarevich group of E / K can be arbitrarily large, where E is an elliptic curve defined over a number field K , with [ K : ] bounded by a constant depending only on p . From this we deduce that the dimension of the p -torsion in the Tate-Shafarevich group of A / can be arbitrarily large, where A is an abelian variety, with dim A bounded by a constant depending only on p .

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