An Sl(2, Z) multiplet of nine-dimensional type II supergravity theories Original Research Article

We show that only by performing generalized dimensional reductions all possible brane configurations are taken into account and one gets the complete lower-dimensional theory. We apply this idea to the reduction of type IIB supergravity in an SL(2, Z)-covariant way and establish T-duality for the type II superstring effective action in the context of generalized dimensional reduction giving the corresponding generalized Buscherʹs T-duality rules.