2004/05/31 by Alexey Anisimov, A Anisimov, Michael Dine +1 · 1 citation
Physics and Astronomy · #Axion #Cosmic string #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Inflation (cosmology) #Noncommutative and Quantum Gravity Theories #Phase (matter) #Phase transition #Simple (philosophy) #Spontaneous symmetry breaking #Symmetry (geometry) #Symmetry breaking #hep-ph
paper · pdf · doi:10.1088/1475-7516/2005/07/009
published as JCAP 0507 (2005) 009 · 14 pages. Several references added
arxiv created 2004/06/27 · openalex publication_date 2005/07/14 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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.