Cosmological Constraints on the Scale of Supersymmetry Breaking

Abstract

The gravitino must be either light enough so that ambient gravitinos would not produce too large a cosmic deceleration, or heavy enough so that almost all gravitinos would have decayed before the time of helium synthesis. The second alternative is shown to allow supersymmetry-breaking scales above a model-dependent lower bound of ${10}^{11}$ to ${10}^{16}$ GeV.