D=10, N=IIB SUPERGRAVITY - LORENTZ-INVARIANT ACTIONS AND DUALITY

We present a manifestly Lorentz invariant and supersymmetric component field action for D = 10, type IIB supergravity, using a newly develop ed method for the construction of actions with chiral bosons, which im plies only a single scalar non propagating auxiliary field. With the s ame method we construct also an action in which the complex two{form g auge potential and its Hodge{dual, a complex six{form gauge potential, appear in a symmetric way in compatibility with supersymmetry and Lor entz invariance. The duals of the two physical scalars of the theory t urn out to be described by a SL(2; R) triplet of eight{forms whose cur vatures are constrained by a single linear relation. We present also a supersymmetric action in which the basic fields and their duals, six{ form and eight{form potentials, appear in a symmetric way. All these a ctions are manifestly invariant under the global SL(2; R){duality grou p of D = 10, IIB supergravity and are equivalent to each other in that their dynamics corresponds to the well known equations of motion of D = 10, IIB supergravity.