On the Realization of MSSM Inflation

We study the fine-tuning problem on the initial condition of inflation in the minimal supersymmetric standard model (MSSM), associated with the narrowness of the slow-roll region. We consider two cases before the onset of the MSSM inflation, namely, the radiation-dominated era and preceding inflationary era. We find that thermal dissipation does not induce additional friction to the inflaton; thus it does not help enlarge the slow-roll region. We argue that thermal correction to the potential in the preceding radiation-dominated era and quantum fluctuations in the preceding inflationary era disturb field configuration and prevent the MSSM inflation unless a certain specific preinflation history is realized.