Dark matter and dark energy from a single scalar field and CMB data
Mar, 2005
26 pages
Published in:
- Astrophys.J. 632 (2005) 691-705
e-Print:
- astro-ph/0503036 [astro-ph]
DOI:
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Abstract: (arXiv)
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 which yields also 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 LCDM, dynamical DE with a SUGRA potential, DE with a SUGRA potential and a constant DE-DM coupling, as well as 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-sigma level. A peculiarity of the dual-axion model with SUGRA potential is to cause more stringent constraints on most parameters and to favor high values of the Hubble parameter.- cosmology: theory
- dark matter
- elementary particles
- dark matter
- dark energy
- field theory: scalar
- strong interaction: CP
- axion: momentum spectrum
- potential
- cosmic background radiation
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