Light moduli in almost no-scale models Original Research Article

We discuss the stabilization of the compact dimension for a class of five-dimensional orbifold supergravity models. Supersymmetry is broken by the superpotential on a boundary. Classically, the size L of the fifth dimension is undetermined, with or without supersymmetry breaking, and the effective potential is of no-scale type. The size L is fixed by quantum corrections to the Kähler potential, the Casimir energy and Fayet–Iliopoulos (FI) terms localized at the boundaries. For an FI scale of order image, as in heterotic string compactifications with anomalous image symmetries, one obtains image. A small mass is predicted for the scalar fluctuation associated with the fifth dimension, image.