New D = 4 gauged supergravities from N=4 orientifolds with fluxes

We consider classes of T6-orientifolds, where the orientifold projection contains an inversion I9−pon 9−p coordinates, transverse to a Dp-brane. In absence of fluxes, the massless sector of these models corresponds to diverse forms of Script N = 4 supergravity, with six bulk vector multiplets coupled to Script N = 4 Yang-Mills theory on the branes. They all differ in the choice of the duality symmetry corresponding to different embeddings of SU(1,1) × SO(6,6+n) in Sp(24+2n,Bbb R), the latter being the full group of duality rotations. Hence, these lagrangians are not related by local field redefinitions. When fluxes are turned on one can construct new gaugings of Script N = 4 supergravity, where the twelve bulk vectors gauge some nilpotent algebra which, in turn, depends on the choice of fluxes.