Pure gravity mediation and chaotic inflation in supergravity

Abstract

We investigate the compatibility of pure gravity mediation (or minimal split supersymmetry) with chaotic inflation models in supergravity. We find that an approximate ${Z}_{2}$ parity of the inflaton is useful to suppress gravitino production from the thermal bath and to obtain consistent inflation dynamics. We discuss the production of the lightest supersymmetric particle through the decay of the inflaton with approximate ${Z}_{2}$ symmetry, and we find that a large gravitino mass is favored in order to avoid overproduction of the lightest supersymmetric particle, while a lower gravitino mass requires the tuning of parameters. This may explain why a gravitino mass of $O(100)\text{ }\text{ }\mathrm{TeV}$ rather than $O(100)\text{ }\text{ }\mathrm{GeV}$ may be natural.