The title is

"Differential Geometry of G2-manifolds",

Abstract:

"Riemannian manifolds in dimension 7 with a smooth vector cross product =
are G2 manifolds. When the cross product is parallel with respect to the =
Levi-Civita connection have their (restricted) holonomy group is =
contained in G2. These manifolds are Ricci-flat. Another condition on =
the covariant derivative of the cross-product results in Einstein =
manifolds. In the talk I will present a recent result [Ivanov&-] that =
shows that a certain Fernandez-Gray class of G2 manifolds contains no =
Einstein metrics.=20

Richard Cleyton