Non-standard fewnomials
Non-standard fewnomials
Call non-standard fewnomial (or sparse/lacunary polynomial) a non-standard polynomial whose number of non-zero terms is finite. The non-standard translation of a conjecture of Rényi and Erdöt
Call non-standard fewnomial (or sparse/lacunary polynomial) a non-standard polynomial whose number of non-zero terms is finite. The non-standard translation of a conjecture of Rényi and Erdöt
We consider profinite groups as 2-sorted first order structures, with a group sort, and a second sort which acts as an index set for a uniformly definable basis of neighbourhoods of the identity. It is shown that if the basis consists of all open subgroups, then the first order theory of such a structure is NIP (that is, does not have the independence property) precisely if the group has a normal subgroup of finite index which is a direct product of finitely many compact p-adic analytic groups, for distinct primes […]
In 1969, Sato and Hörmander introduced the notion of wave front set of a distribution in the real context. This concept gives a better understanding of operations on distributions such as product or pullback and it plays an important role in the theory of partial differential equations. In 1981, Howe introduced a notion of wave front set for some Lie group representations and in 1985, Heifetz gave an analogous version in the p-adic context. In this talk, in the t-adic context in characteristic zero, using Cluckers-Loeser motivic integration we will […]
We show that irreducibility of a polynomial in any number of variables over a number field is a diophantine condition, i.e. captured by an existential formula. This generalises a previous result by Colliot-Thélène and Van Geel that the set of non-nth-powers is diophantine for any n. Our method is heavily based on the Brauer group, originating from Poonen's use of quaternion algebras as a technical tool for first-order definitions in number fields.
Siegel proved the finiteness of the set of solutions to the unit equation in a number ring, i.e., for a number field K with ring of integers O, the equation x+y=1 has only finitely many solutions in O*. That is, reformulated in more algebro-geometric terms, the hyperbolic curve P^1-{0,1,infinite} has only finitely many 'integral points'. In 1983, Faltings proved the Mordell conjecture generalizing Siegel's theorem: a hyperbolic complex algebraic curve has only finitely many integral points. Inspired by Faltings's and Siegel's finiteness results, Lang and Vojta formulated a general finiteness […]
Gauss a donné des formules pour le nombre de points entiers primitifs de la 2-sphère de rayon au carré égal à n. Ces formules sont en termes de nombres de classes d'anneaux quadratiques de discriminant étroitement liés à n. Cela mène à la question de savoir si ceci peut être expliqué par une action libre et transitive du groupe de Picard de cet anneau sur l'ensemble des tels points entiers primitifs à symétries globales SO_3(Z) près. Ceci est en effet le cas, et cette action peut être explicitée. L'outil utilisé […]