The Gravitino-Overproduction Problem in Inflationary Universe
نویسندگان
چکیده
We show that the gravitino-overproduction problem is prevalent among inflation models in supergravity. An inflaton field φ generically acquires (effective) nonvanishing auxiliary field G Φ , if the Kähler potential is non-minimal. The inflaton field then decays into a pair of the gravitinos. We extensively study the cosmological constraints on G Φ for a wide range of the gravitino mass. For many inflation models we explicitly estimate G Φ , and show that the gravitino-overproduction problem severely constrains the inflation models, unless such an interaction as K = κ/2 |φ|2z2+h.c. is suppressed (here z is the field responsible for the supersymmetry breaking). We find that many of them are already excluded or on the verge of, if κ ∼ O(1).
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