Abstract
A model of high scale inflation is presented where the radial part of the Peccei-Quinn (PQ) field with a non-minimal coupling to gravity plays the role of the inflaton, and the QCD axion is the dark matter. A quantum fluctuation of in the axion field will result in a smaller angular fluctuation if the PQ field is sitting at a larger radius during inflation than in the vacuum. This changes the effective axion decay constant, , during inflation and dramatically reduces the production of isocurvature modes. This mechanism opens up a new window in parameter space where an axion decay constant in the range is compatible with observably large . The exact range allowed for depends on the efficiency of reheating. This model also predicts a minimum possible value of . The new window can be explored by a measurement of possible with SPIDER and the proposed CASPEr experiment search for high axions.
- Received 15 October 2014
DOI:https://doi.org/10.1103/PhysRevD.91.023509
© 2015 American Physical Society