Convergents and irrationality measures of logarithms.
We continue the investigation of convolutions of second order linear recursive sequences (see the first part in [1]). In this paper, we focus on the case when the characteristic polynomials of the sequences have common root.
For n ∈ ℕ, L > 0, and p ≥ 1 let be the largest possible value of k for which there is a polynomial P ≢ 0 of the form , , , such that divides P(x). For n ∈ ℕ, L > 0, and q ≥ 1 let be the smallest value of k for which there is a polynomial Q of degree k with complex coefficients such that . We find the size of and for all n ∈ ℕ, L > 0, and 1 ≤ p,q ≤ ∞. The result about is due to Coppersmith and Rivlin, but our proof is completely different and much shorter even in that special...
We use the estimation of the number of integers such that belongs to an arithmetic progression to study the coprimality of integers in , , .
Let be a family of Mumford-type, that is, a family of polarized complex abelian fourfolds as introduced by Mumford in [9]. This family is defined starting from a quaternion algebra over a real cubic number field and imposing a condition to the corestriction of such . In this paper, under some extra conditions on the algebra , we make this condition explicit and in this way we are able to describe the polarization and the complex structures of the fibers. Then, we look at the non simple -fibers...
Soit un objet algébrique (par exemple une courbe ou un revêtement) défini sur et de corps des modules un corps de nombres . Il est bien connu que n’admet pas nécessairement de -modèle. En utilisant deux résultats récents dus à P. Dèbes, J.-C. Douai et M. Emsalem nous donnerons un majorant pour le degré d’un corps de définition de sur . Dans une deuxième partie, nous donnerons des conditions suffisantes sur l’ordre de Aut() pour que admette un -modèle.