String Effective Actions and Cosmological Stability of Scalar Potentials
  The cosmology of the string effective action, including one loop string threshold corrections, is analyzed for static compactifications. The stability of the minima of a general supersymmetry breaking potential is studied in the presence of radiation. In particular, it is shown that the radiation bath makes the minima with negative cosmological constant unstable. 
Juan Garcia-Bellido and Mariano Quiros