Auteur / Autrice : | Pierre Le Boudec |
Direction : | Régis de La Bretèche |
Type : | Thèse de doctorat |
Discipline(s) : | Mathématiques |
Date : | Soutenance en 2012 |
Etablissement(s) : | Paris 7 |
Mots clés
Mots clés contrôlés
Résumé
In this thesis, we are interested in counting rational points on certain algebraic varieties. A conjecture of Manin predicts precisely the asymptotic behaviour of the number of rational points of bounded height on Fano varieties. Our main goal is to prove Manin's conjecture for some examples of del Pezzo surfaces defined over Q. For this, we resort to universal torsors to parametrize the rational points and then we make use of various analytic number theory results, such as for instance the equidistribution of the values of certain divisor functions in arithmetic progressions. To begin with, we deal in a first part with the cases of three quartic del Pezzo surfaces, whose singularity types are respectively 3A1, A1+A2 and A3. Afterwards, we deal in a second part with the cases of two cubic surfaces, whose singularity types are respectively 2A2+A1 and D4. The former is only the third example of non-toric cubic surface for which Manin's conjecture is proved. Note in addition that the work about the latter improves on a result of Browning and answers a problem initially posed by Tschinkel. Finally, in an appendix, as another application of the equidistribution results mentioned above, we establish an asymptotic formula for the number of power-free values of the r variables polynomial t1⋯tr−1.