Production and dilution of gravitinos by modulus decay

We study the cosmological consequences of generic scalar fields like moduli which decay only through gravitationally suppressed interactions. We consider a new production mechanism of gravitinos from moduli decay, which might be more effective than previously known mechanisms, and calculate the final gravitino-to-entropy ratio to compare with the constraints imposed by successful big bang nucleosynthesis (BBN) etc., taking possible hadronic decays of gravitinos into account. We find the modulus mass smaller than similar to10(4) TeV is excluded. On the other hand, inflation models with high reheating temperatures T(R,inf)similar to10(16) GeV can be compatible with BBN thanks to the late-time entropy production from the moduli decay if model parameters are appropriately chosen.