• Editors' Suggestion

Axion Cold Dark Matter in View of BICEP2 Results

Paolo Gondolo and Luca Visinelli
Phys. Rev. Lett. 113, 011802 – Published 2 July 2014

Abstract

The properties of axions that constitute 100% of cold dark matter (CDM) depend on the tensor-to-scalar ratio r at the end of inflation. If r=0.200.05+0.07 as reported by the BICEP2 Collaboration, then “half” of the CDM axion parameter space is ruled out. Namely, in the context of single-field slow-roll inflation, for axions to be 100% of the CDM, the Peccei-Quinn symmetry must be broken after the end of inflation, so that axion nonadiabatic primordial fluctuations are compatible with observational constraints. The cosmic axion density is then independent of the tensor-to-scalar ratio r, and the axion mass is expected to be in a narrow range that, however, depends on the cosmological model before primordial nucleosynthesis. In the standard Lambda CDM cosmology, the CDM axion mass range is ma=(71±2μeV)(αdec+1)6/7, where αdec is the fractional contribution to the cosmic axion density from decays of axionic strings and walls.

  • Figure
  • Received 7 April 2014

DOI:https://doi.org/10.1103/PhysRevLett.113.011802

© 2014 American Physical Society

Authors & Affiliations

Paolo Gondolo* and Luca Visinelli

  • Department of Physics and Astronomy, University of Utah, 115 S 1400 E Rm. 201, Salt Lake City, Utah 84112, USA

  • *paolo.gondolo@utah.edu
  • luca.visinelli@utah.edu

See Also

Tensor Interpretation of BICEP2 Results Severely Constrains Axion Dark Matter

David J. E. Marsh, Daniel Grin, Renée Hlozek, and Pedro G. Ferreira
Phys. Rev. Lett. 113, 011801 (2014)

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 113, Iss. 1 — 4 July 2014

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×