Orateur(s)  Mark Haskins  Londres,

Titre  New G2 holonomy cones and exotic nearly Kähler structures on the 6sphere and on the product of two 3spheres 
Date  07/04/2015 
Horaire  14:00 à 15:00 

Résume  A longstanding problem in almost complex geometry has been the question of existence of (complete) inhomogeneous nearly Kähler 6manifolds. One of the main motivations for this question comes from geometry: the Riemannian cone over a nearly Kähler 6manifold is a singular space with holonomy G2. Viewing Euclidean 7space as the cone over the round 6sphere, the induced nearly Kähler structure is the standard G2invariant almost complex structure on the 6sphere induced by octonionic multiplication. We resolve this problem by proving the existence of exotic (inhomogeneous) nearly Kahler metrics on the 6sphere and also on the product of two 3spheres. This is joint work with Lorenzo Foscolo, Stony Brook. 
Salle  Barre 1525, 5ème étage, salle 02 
Adresse  Campus Pierre et Marie Curie 