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The Gravitino-Overproduction Problem in Inflationary Universe

Masahiro Kawasaki·Fuminobu Takahashi·T. T. Yanagida
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Abstract

We show that the gravitino-overproduction problem is prevalent among inflation models in supergravity. An inflaton field ϕgenerically acquires (effective) non-vanishing 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_ϕfor 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|^2 z^2 + 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\sim O(1).

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Masahiro Kawasaki, Fuminobu Takahashi, T. T. Yanagida. 2006-08-18. The Gravitino-Overproduction Problem in Inflationary Universe. https://doi.org/10.1103/physrevd.74.043519

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