Is There a Peccei-Quinn Phase Transition?

Abstract

The nature of axion cosmology is usually said to depend on whether the Peccei-Quinn (PQ) symmetry breaks before or after inflation. The PQ symmetry itself is believed to be an accident, so there is not necessarily a symmetry during inflation at all. We explore these issues in some simple models, which provide examples of symmetry breaking before and after inflation, or in which there is no symmetry during inflation and no phase transition at all. One effect of these observations is to relax the constraints from isocurvature fluctuations due to the axion during inflation. We also observe new possibilities for evading the constraints due to cosmic strings and domain walls, but they seem less generic.

14 pages. Several references added

References in corpus (4)

• de Sitter Vacua in String Theory
• Bounds on isocurvature perturbations from CMB and LSS data
• Supersymmetry, Axions and Cosmology
• The Peccei-Quinn Field as Curvaton

Cited by in corpus (14)

• Cosmological Moduli and the Post-Inflationary Universe: A Critical Review
• Unification of Inflation with Dark Energy in $f(R)$ Gravity and Axion Dark Matter
• Geometric Inflation and Dark Energy with Axion $F(R)$ Gravity
• Axions, Instantons, and the Lattice
• Adiabatic suppression of the axion abundance and isocurvature due to coupling to hidden monopoles
• Comments on Axions, Domain Walls, and Cosmic Strings
• High-Scale Axions without Isocurvature from Inflationary Dynamics
• Isocurvature Perturbations of Dark Energy and Dark Matter from the Swampland Conjecture
• Diraxiogenesis
• Inflaxion Dark Matter
• Dark Matter and Baryon Asymmetry from the very Dawn of Universe
• Cosmological relaxation and high scale inflation
• Axion production from primordial magnetic fields
• Phase transition in a supersymmetric axion model