Moduli mediation without moduli-induced gravitino problem

Abstract

We study the moduli-induced gravitino problem within the framework of the phenomenologically attractive mirage mediations. The huge amount of gravitino generated by the moduli decay can be successfully diluted by introducing an extra light modulus field which does not induce the supersymmetry breaking. Since the lifetime of extra modulus field becomes longer than usually considered modulus field, our proposed mechanism is applied to both the low- and high-scale supersymmetry breaking scenarios. We also point out that such an extra modulus field appears in the flux compactification of type II string theory

String Cosmology: from the Early Universe to Today

“…Building on the original work, further studies of the moduli-induced gravitino problem have been performed in [729,730,731,732,733,734,735,736,737,738,739,740,741,742,743,744].…”

Constraints on small-field axion inflation

“…It is then possible to avoid the isocurvature constraint by the low-scale inflation, although the upper bound of f QCD depends on the initial misalignment angle of the axion and dilution mechanism after the inflation [9,10,11]. Recently, some of the authors conjectured that, in a certain class of small-field axion inflation derived from type IIB superstring theory [12], 1 the tensor-to-scalar ratio r correlates with the axion decay constant f as follows [13],…”

“…3. Here and in the following analysis, we employ the maximal value of the QCD axion decay constant constrained by the upper bound of dark matter abundance, although it depends on the initial misalignment angle of the axion and dilution mechanism after the inflation [9,10,11]. As can be seen in Fig.…”

Small field axion inflation with sub-Planckian decay constant

“…In general, supersymmetric models have the gravitino problem, and the low-energy effective field theory derived from superstring theory has the moduli problem. The non-thermally produced gravitinos from the moduli decay could be still a problem, and a light moduli, which does not contribute to supersymmetry breaking, can help in diluting the relic abundance of unwanted particles [38]. The baryogenesis at a low temperature can be also a concern, and the low-energy scale Affleck-Dine mechanism can be a possibility in our scenarios to realize the desired baryon asymmetry of the Universe [39,40].…”