2014/07/28 by Takeo Moroi, Kyohei Mukaida, Kazunori Nakayama +1 · 1 citation
Physics and Astronomy · #Axion #Cosmology and Gravitation Theories #Curvature #Dark Matter and Cosmic Phenomena #Dark radiation #False vacuum #Inflation (cosmology) #Inflaton #Particle physics theoretical and experimental studies #Scalar (mathematics) #Scalar potential #Supersymmetry #Symmetry (geometry) #astro-ph.CO #hep-ph
paper · pdf · doi:10.1007/jhep11(2014)151
18 pages, 4 figures
arxiv created 2014/07/28 · openalex publication_date 2014/11/01 · arxiv updated 2015/06/22 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We revisit the cosmological aspects of axion models. In the high-scale inflation scenario, the Peccei-Quinn (PQ) symmetry is likely to be restored during/after inflation. If the curvature of the PQ scalar potential at the origin is smaller than its vacuum expectation value; for instance in a class of SUSY axion models, thermal inflation happens before the radial component of the PQ scalar (saxion) relaxes into the global minimum of the potential and the decay of saxion coherent oscillation would produce too much axion dark radiation. In this paper, we study how to avoid the overproduction of axion dark radiation with some concrete examples. We show that, by taking account of the finite-temperature dissipation effect appropriately, the overproduction constraint can be relaxed since the PQ scalar can take part in the thermal plasma again even after the PQ phase transition. We also show that it can be further relaxed owing to the late time decay of another heavy CP-odd scalar, if it is present.