Informal Pizza Seminar

A note on the moduli-induced gravitino problem

Natalia Shuhmaher

McGill University

Gravitino problem has been recently revised in the contest of heavy moduli decay. It had been shown that even uplifting of the moduli above 100 TeV scale does not resolve the cosmological moduli problem. The large branching ratio of heavy moduli into gravitino causes overproduction of gravitino and, therefore, it is incompatible with Standard Cosmology. Typically, in the literature, the treatment of moduli-induced gravitino problem does not include nonperturbative decay channels. In the following, we introduce a way to overcome the moduli-induced gravitino problem making use of the tachyonic decay of moduli into Standard Model degrees of freedom, e.g Higgs particles. Rough estimates on model dependent parameters set a lower bound on the allowed moduli between 10⁷-10⁸ GeV.