Séminaires : Séminaire d'Algèbre

Equipe(s) : gr,
Responsables :J. Alev, D. Hernandez, B. Keller, Th. Levasseur, et S. Morier-Genoud.
Email des responsables : Jacques Alev <jacques.alev@univ-reims.fr>, David Hernandez <david.hernandez@imj-prg.fr>, Bernhard Keller <bernhard.keller@imj-prg.fr>, Thierry Levasseur <Thierry.Levasseur@univ-brest.fr>, Sophie Morier-Genoud <sophie.morier-genoud@imj-prg.fr>
Salle : à distance / remote
Adresse :IHP

Depuis le 23 mars 2020, le séminaire se tient à distance. Pour les liens et mots de passe, merci de contacter l'un des organisateurs ou de souscrire à la liste de diffusion https://listes.math.cnrs.fr/wws/info/paris-algebra-seminar. L'information nécessaire sera envoyée par courrier électronique peu avant chaque exposé. Les notes et transparents sont disponibles ici.


Since March 23, 2020, the seminar has been taking place remotely. For the links and passwords, please contact one of the organizers or

subscribe to the mailing list at https://listes.math.cnrs.fr/wws/info/paris-algebra-seminar. The connexion information will be emailed shortly before each talk. Slides and notes are available here.


Orateur(s) Susan SIERRA - Edimbourg,
Titre Dynamics of automorphisms, noetherian rings, and the Virasoro algebra
Horaire14:00 à 15:00
RésumeThis talk links algebraic geometry, noncommutative ring theory, and the Virasoro Lie algebra, known for its importance in conformal field theory. We begin with a question in ring theory. Let X be a projective surface with an automorphism a, and consider the skew polynomial extension k(X)[t; a]. Which finitely generated graded subalgebras are noetherian? It turns out that, morally, if a has dense orbits on X there are many noetherian subalgebras, and if not there are few. In the first part of the talk we explain this. In the second, we show how this leads to a proof that the enveloping algebra of the Virasoro algebra is not noetherian.
Salleà distance / remote