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arXiv · 2105.05771

Spontaneous breaking of the Peccei-Quinn symmetry during warm inflation

João G. Rosa·Luís B. Ventura
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Abstract

We show that, for values of the axion decay constant parametrically close to the GUT scale, the Peccei-Quinn phase transition may naturally occur during warm inflation. This results from interactions between the Peccei-Quinn scalar field and the ambient thermal bath, which is sustained by the inflaton field through dissipative effects. It is therefore possible for the axion field to appear as a dynamical degree of freedom only after observable CMB scales have become super-horizon, thus avoiding the large-scale axion isocurvature perturbations that typically plague such models. This nevertheless yields a nearly scale-invariant spectrum of axion isocurvature perturbations on small scales, with a density contrast of up to a few percent, which may have a significant impact on the formation of gravitationally-bound axion structures such as mini-clusters.

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João G. Rosa, Luís B. Ventura. 2021-05-12. Spontaneous breaking of the Peccei-Quinn symmetry during warm inflation. https://arxiv.org/abs/2105.05771

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