Thomas Vogel (IAS/UPenn): Existence of Engel stucturess
Abstract:
Engel structures are non-integrable plane fields on 4-manifolds who
share many properties with contact structures. The existence of an
Engel structure on a manifolds leads to strong restrictions on the
topology of the manifold: Under certain orientation assumptions the
tangent bundle of the manifold is trivial.
In this talk we develop a construction which shows that the converse is
also true: Every 4-manifold with trivial tangent bundle admits an Engel
structure.