TY - JOUR

T1 - Cosmological moduli problem from thermal effects

AU - Nakayama, Kazunori

AU - Takahashi, Fuminobu

N1 - Funding Information:
This work was supported by World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan. K.N. would like to thank the Japan Society for the Promotion of Science for financial support.

PY - 2009/1/5

Y1 - 2009/1/5

N2 - We estimate the cosmological abundance of a modulus field that has dilatonic couplings to gauge fields, paying particular attention to thermal corrections on the modulus potential. We find that a certain amount of the modulus coherent oscillations is necessarily induced by a linear thermal effect. We argue that such an estimate provides the smallest possible modulus abundance for a given thermal history of the Universe. As an example we apply our results to a saxion, a bosonic supersymmetric partner of an axion, and derive a tight bound on the reheating temperature. We emphasize that the problem cannot be avoided by fine-tuning the initial deviation of the modulus field, since the minimal amount of the modulus is induced by the dynamics of the scalar potential.

AB - We estimate the cosmological abundance of a modulus field that has dilatonic couplings to gauge fields, paying particular attention to thermal corrections on the modulus potential. We find that a certain amount of the modulus coherent oscillations is necessarily induced by a linear thermal effect. We argue that such an estimate provides the smallest possible modulus abundance for a given thermal history of the Universe. As an example we apply our results to a saxion, a bosonic supersymmetric partner of an axion, and derive a tight bound on the reheating temperature. We emphasize that the problem cannot be avoided by fine-tuning the initial deviation of the modulus field, since the minimal amount of the modulus is induced by the dynamics of the scalar potential.

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U2 - 10.1016/j.physletb.2008.11.046

DO - 10.1016/j.physletb.2008.11.046

M3 - Article

AN - SCOPUS:57649083568

SN - 0370-2693

VL - 670

SP - 434

EP - 436

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

IS - 4-5

ER -