2005/03/31 by Roberto Mainini, L. P. L. Colombo, Loris P. L. Colombo +2 · 1 citation
Physics and Astronomy · #Astrophysics #Axion #CMB cold spot #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark energy #Dark matter #Hubble's law #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum mechanics #Scalar field dark matter #Strong CP problem #Supergravity #Supersymmetry #Theoretical physics #astro-ph
paper · pdf · doi:10.1086/433163
published as Astrophys.J. 632 (2005) 691-705 · 34 pages, 15 figures, replaced with accepted version
arxiv created 2005/07/01 · openalex publication_date 2005/10/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Axions are likely to be the dark matter (DM) that cosmological data require. They arise in the Peccei-Quinn solution of the strong-CP problem. In a previous work we showed that their model has a simple and natural generalization that also yields dark energy (DE), in fair proportions, without tuning any parameter: DM and DE arise from a single scalar field and are weakly coupled in the present era. In this paper we extend the analysis of this dual-axion cosmology and fit it to WMAP data, by using a Markov chain technique. We find that ΛCDM, dynamical DE with a SUGRA potential, DE with a SUGRA potential and a constant DE-DM coupling, and the dual-axion model with a SUGRA potential fit data with a similar accuracy. The best-fit parameters are, however, fairly different, although consistency is mostly recovered at the 2 σ level. A peculiarity of the dual-axion model with a SUGRA potential is to cause more stringent constraints on most parameters and to favor high values of the Hubble parameter.