Inflationary axion cosmology
Abstract
If PecceiQuinn (PQ) symmetry is broken after inflation, the initial axion angle is a random variable on cosmological scales; based on this fact, estimates of the relicaxion mass density give too large a value if the axion mass is less than about 10^{6} eV. This bound can be evaded if the Universe underwent inflation after PQ symmetry breaking and if the observable Universe happens to be a region where the initial axion angle was atypically small, θ_{1}<~[m_{a}/(10^{6} eV]^{0.59}.] We show consideration of fluctuations induced during inflation severely constrains the latter alternative.
 Publication:

Physical Review Letters
 Pub Date:
 January 1991
 DOI:
 10.1103/PhysRevLett.66.5
 Bibcode:
 1991PhRvL..66....5T
 Keywords:

 Broken Symmetry;
 Cosmology;
 Particle Theory;
 Quantum Chromodynamics;
 Supersymmetry;
 Dark Matter;
 Relic Radiation;
 String Theory;
 Astrophysics;
 98.80.Cq;
 14.80.Gt;
 Particletheory and fieldtheory models of the early Universe