Séminaires : Séminaire d'Analyse et Géométrie

Equipe(s) :
Responsables :O. Biquard, A. Deruelle, I. Itenberg, X. Ma
Email des responsables : {olivier.biquard, alix.deruelle, ilia.itenberg, xiaonan.ma}@imj-prg.fr
Salle : 15–25.502
Adresse :Jussieu

Orateur(s) Mark Haskins - Londres,
Titre New G2 holonomy cones and exotic nearly Kähler structures on the 6-sphere and on the product of two 3-spheres
Horaire14:00 à 15:00
RésumeA long-standing problem in almost complex geometry has been the question of existence of (complete) inhomogeneous nearly Kähler 6-manifolds. One of the main motivations for this question comes from geometry: the Riemannian cone over a nearly Kähler 6-manifold is a singular space with holonomy G2. Viewing Euclidean 7-space as the cone over the round 6-sphere, the induced nearly Kähler structure is the standard G2-invariant almost complex structure on the 6-sphere induced by octonionic multiplication. We resolve this problem by proving the existence of exotic (inhomogeneous) nearly Kahler metrics on the 6-sphere and also on the product of two 3-spheres. This is joint work with Lorenzo Foscolo, Stony Brook.