Site Web DMA

Bannière DMA Site de l'ENS Site Paris Sciences et Lettres Site du CNRS Accueil

Séminaire Géométrie et théorie des modèles

Horaires : Le vendredi 10 mars 2017, 14h15

Lieu : ENS, salle W

Quasianalytic Ilyashenko algebras

Patrick Speissegger (Konstanz/McMaster)

In 1923, Dulac published a proof of the claim that every real analytic vector field on the plane has only finitely many limit cycles (now known as Dulac's Problem). In the mid-1990s, Ilyashenko completed Dulac's proof; his completion rests on the construction of a quasianalytic class of functions. Unfortunately, this class has very few known closure properties. For various reasons I will explain, we are interested in constructing a larger quasianalytic class that is also a Hardy field. This can be achieved using Ilyashenko's idea of superexact asymptotic expansion. (Joint work with Zeinab Galal and Tobias Kaiser)


Autres séances du séminaire

45 rue d'Ulm - F 75230 PARIS cedex 05 | phone : (33) 1 44 32 20 49 | fax : (33) 1 44 32 20 69

Plan du site | Mentions légales | | Edition du site | Web site designed under SPIP