Diluting the inflationary axion fluctuation by a stronger QCD in the early Universe
arXiv:1505.00306 · doi:10.1016/j.physletb.2015.08.041
Abstract
We propose a new mechanism to suppress the axion isocurvature perturbation, while producing the right amount of axion dark matter, within the framework of supersymmetric axion models with the axion scale induced by supersymmetry breaking. The mechanism involves an intermediate phase transition to generate the Higgs μ-parameter, before which the weak scale is comparable to the axion scale and the resulting stronger QCD yields an axion mass heavier than the Hubble scale over a certain period. Combined with that the Hubble-induced axion scale during the primordial inflation is well above the intermediate axion scale at present, the stronger QCD in the early Universe suppresses the axion fluctuation to be small enough even when the inflationary Hubble scale saturates the current upper bound, while generating an axion misalignment angle of order unity.
5 pages, 1 figure; v2: discussion extended, references added, typos corrected
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- Axion Isocurvature and Magnetic Monopoles
- Strongly broken Peccei-Quinn symmetry in the early Universe
- Axion Misalignment Driven to the Bottom
- Adiabatic suppression of the axion abundance and isocurvature due to coupling to hidden monopoles
- High-Scale Axions without Isocurvature from Inflationary Dynamics
- Isocurvature Perturbations of Dark Energy and Dark Matter from the Swampland Conjecture
- Curvaton as dark matter with secondary inflation
- Affleck-Dine Leptogenesis with Varying Peccei-Quinn Scale
- Pseudo-Nambu-Goldstone inflation with twin waterfalls
- Kination cosmology from scalar fields and gravitational-wave signatures
- Axions in Type IIA Superstring Theory and Dark Matter