N=1 No-Scale Supergravity from IIB Orientifolds

Abstract

We describe the low-energy effective theory of N=1 spontaneously broken supegravity obtained by flux-induced breaking in the presence of n D3 branes. This theory can be obtained by integrating out three massive gravitino multiplets in the hierarchical breaking N=4 to N=3 to N=2 to N=1. This integration also eliminates the IIB complex dilaton. The resulting theory is a no-scale supergravity model, whose moduli are the three chiral multiplets that correspond to the three radii of the three 2-tori in 6-torus, together with the 6n brane coordinates. The U(n) gauge interactions on the branes respect the no-scale structure,and the N=1 goldstino is the fermionic partner of the 6-torus volume.