4-D gauged supergravity analysis of type IIB vacua on K3xT2/Z2

We analyze N = 2, 1, 0 vacua of type-IIB string theory on K3 x T-2/Z(2) orientifold in presence of three-form fluxes from a four dimensional supergravity viewpoint. The quaternionic geometry of the K3 moduli space together with the special geometry of the NS and R-R dilatons and of the T-2-complex structure moduli play a crucial role in the analysis. The introduction of fluxes corresponds to a particular gauging of N = 2, D = 4 supergravity. Our results agree with a recent work of Tripathy and Trivedi. The present formulation shows the power of supergravity in the study of effective theories with broken supersymmetry.