Wednesday 1 February 2017, 16:00 - 17:00 in HG03.085
Paolo Antonini (SISSA Trieste)
Integrable lifts and quotients for transitive Lie algebroids
In this seminar we report on work in progress with Iakovos Androulidakis and
Ioan Marcut concerning the integrability problem of Lie algebroids.
In many constructions in non commutative geometry the passage from a singular space to a C* algebra involves the use of a Lie groupoid as an intermediate desingularization space.
The infinitesimal datum of a Lie groupoid is a Lie algebroid and they appear independently for instance in:
-theory of foliations
However in general is not possible to integrate a Lie algebroid to a Lie groupoid ( in contrast to the theory of Lie algebras). The first part of the talk will be concerned with the discussion of Lie algebroids: basic definitions, examples, the integration problem, the obstructions to the integrability of Crainic-Fernandes and the discussion of an important non integrable example given by Molino.
In the last part we will explain our ideas of "removing" the obstructions of a transitive algebroid, passing to a suitable extension or quotient. In these cases one could still perform some of the basic constructions in index theory and non commutative geometry.