Magnetic fluxes and moduli stabilization Original Research Article

Stabilization of closed string moduli in toroidal orientifold compactifications of type IIB string theory are studied using constant internal magnetic fields on D-branes and 3-form fluxes that preserve image supersymmetry in four dimensions. Our analysis corrects and extends previous work by us, and indicates that charged scalar VEVʹs need to be turned on, in addition to the fluxes, in order to construct a consistent supersymmetric model. As an explicit example, we first show the stabilization of all Kähler class and complex structure moduli by turning on magnetic fluxes on different sets of D9-branes that wrap the internal space image in a compactified type I string theory, when a charged scalar on one of these branes acquires a non-zero VEV. The latter can also be determined by adding extra magnetized branes, as we demonstrate in a subsequent example. In a different model with magnetized D7-branes, in a IIB orientifold on image, we show the stabilization of all the closed string moduli, including the axion-dilaton at weak string coupling image, by turning on appropriate closed string 3-form fluxes.