New D=4 gauged supergravities from N=4 orientifolds with fluxes -: art. no. 015

We consider classes of T-6-orientifolds, where the orientifold projection contains an inversion I9-p on 9 - p coordinates, transverse to a Dp-brane. In absence of fluxes, the massless sector of these models corresponds to diverse forms of N = 4 supergravity, with six bulk vector multiplets coupled to JV = 4 Yang-Mills theory on the branes. They all differ in the choice of the duality symmetry corresponding to different embeddings of SU(l,1) x SO(6, 6+n) in Sp(24+2n, 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 JV = 4 supergravity, where the twelve bulk vectors gauge some nilpotent algebra which, in turn, depends on the choice of fluxes.