Abstract
The serious cosmological problems created by the axion-string–axion-domain-wall system in standard axion models are alleviated by positing the existence of a new confining force. The instantons of this force can generate an axion potential that erases the axion strings long before QCD effects become important, thus preventing QCD-generated axion walls from ever appearing. Axion walls generated by the new confining force would decay so early as not to contribute significantly to the energy in axion dark matter.
- Received 16 July 2014
DOI:https://doi.org/10.1103/PhysRevLett.113.241301
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