| Equipe(s) : | tga, |
| Responsables : | Najib Idrissi et Emmanuel Wagner |
| Email des responsables : | najib.idrissi-kaitouni@u-paris.fr, emmanuel.wagner@imj-prg.fr |
| Salle : | 1013 |
| Adresse : | Sophie Germain |
| Description | Un plan d’accès est disponible ici. Pour vous inscrire à la liste de diffusion du séminaire, veuillez vous rendre à cette adresse. |
| Orateur(s) | Oliver Singh - Durham University, |
| Titre | [K-OS] Pseudo-isotopies and diffeomorphisms of 4-manifolds |
| Date | 24/02/2022 |
| Horaire | 14:00 à 15:00 |
| |
| Diffusion | https://lrobert.perso.math.cnrs.fr/join-kos.html |
| Résume | I will talk about pseudo-isotopy, a notion important for understanding
self-diffeomorphisms of manifolds up to isotopy. Pseudo-isotopies of
manifolds in dimensions 5 and up were understood in the 70s by work of
Cerf for simply connected manifolds, and by Hatcher and Wagoner in the
non-simply connected case, using invariants from algebraic
K-theory. Quinn later proved Cerfâs result topologically in dimension
4, leading to a classification of self-homeomorphisms of simply
connected 4-manifolds up to isotopy. I will talk about my work on what Hatcher and Wagonerâs K-theoretic invariants can say about pseudo-isotopies of non-simply connected 4-manifolds, and how they can be used to construct diffeomorphisms of certain 4-manifolds which are pseudo-isotopic but not isotopic to the identity. |
| Salle | 1016 |
| Adresse | Sophie Germain |