Conformal symmetry, dilaton and Weyl invariance

In the talk I’ll discuss how to implement spontaneous breaking of conformal symmetry at the quantum level.  In 
other words how to introduce consistently the massless dilaton. I’ll present several explicit computations and the 
outline of a general iterative procedure. I’ll also comment on the role of the Weyl invariance in the construction. 
Lastly I’ll discuss the relation between conformal symmetry in flat space and Weyl invariance.