Abstract
It has been argued that quantum gravitational effects will violate all nonlocal symmetries. Peccei-Quinn symmetries must therefore be an "accidental" or automatic consequence of local gauge symmetry. Moreover, higher-dimensional operators suppressed by powers of are expected to explicitly violate the Peccei-Quinn symmetry. Unless these operators are of dimension , axion models do not solve the strong problem in a natural fashion. A small gravitationally induced contribution to the axion mass has little if any effect on the density of relic axions. If these operators can solve the axion domain-wall problem, and we describe a simple class of Kim-Shifman-Vainshtein-Zakharov axion models where this occurs. We also study the astrophysics and cosmology of "heavy axions" in models where .
- Received 21 February 1992
DOI:https://doi.org/10.1103/PhysRevD.46.539
©1992 American Physical Society