Inflation and supersymmetry breaking

We study the connection between inflation and supersymmetry breaking in the context of an OʹRaifeartaigh model which can account for both hybrid inflation and a true vacuum where supersymmetry is spontaneously broken. For a weakly coupled inflaton field, the dynamics during the inflationary phase can be determined by the supersymmetry breaking scale MS∼1010 GeV, even if HI⪢m3/2. The spectrum of density fluctuations is then almost scale invariant, with a spectral index n−1=O(MG2/MP2). The mass parameter MG of the OʹRaifeartaigh model is determined by the COBE normalization for the cosmic microwave background to be the grand unification scale, MG∼1016 GeV.