2013/07/31 by Maria Archidiacono, Steen Hannestad, Alessandro Mirizzi +3
Physics and Astronomy · #Astronomy #Astrophysics #Axion #CMB cold spot #Cold dark matter #Cosmic background radiation #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark energy #Dark matter #Hubble's law #Neutrino #Particle physics #Particle physics theoretical and experimental studies #Physics #Planck #Quantum mechanics #astro-ph.CO #hep-ph
paper · pdf · doi:10.1088/1475-7516/2013/10/020
published as JCAP 1310 (2013) 020 · 20 pages, 8 figures, matches version published in JCAP 1310 (2013) 020
openalex publication_date 2013/10/11 · arxiv created 2013/10/21 · arxiv updated 2015/02/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We use cosmological observations in the post-Planck era to derive limits on thermally produced cosmological axions. In the early universe such axions contribute to the radiation density and later to the hot dark matter fraction. We find an upper limit m a < 0.67 eV at 95% C.L. after marginalising over the unknown neutrino masses, using CMB temperature and polarisation data from Planck and WMAP respectively, the halo matter power spectrum extracted from SDSS-DR7, and the local Hubble expansion rate H 0 released by the Carnegie Hubble Program based on a recalibration of the Hubble Space Telescope Key Project sample. Leaving out the local H 0 measurement relaxes the limit somewhat to 0.86 eV, while Planck+WMAP alone constrain the axion mass to 1.01 eV, the first time an upper limit on m a has been obtained from CMB data alone. Our axion limit is therefore not very sensitive to the tension between the Planck-inferred H 0 and the locally measured value. This is in contrast with the upper limit on the neutrino mass sum, which we find here to range from Σ m ν < 0.27 eV at 95% C.L. combining all of the aforementioned observations, to 0.84 eV from CMB data alone.