Abstract

Cosmological constraints when the gravitino is the lightest superparticle are studied. From the condition that the relic gravitinos should not overclose the universe, the upper bound on the reheating temperature of the universe is found to be 102–1010 GeV in a range of gravitino mass 10−5–10 GeV. Furthermore, if the decay of the next-to-the-lightest superparticle produces sizable high energy photons, constraints from the light element (D, 3He, 4He) photodestruction exclude a range of the gravitino mass.