Dark energy scaling from dark matter to acceleration
| Autor: | Eric V. Linder, Robert R. Caldwell, Jannis Bielefeld |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Physics
Nuclear and High Energy Physics Cosmology and Nongalactic Astrophysics (astro-ph.CO) Hot dark matter Scalar field dark matter FOS: Physical sciences General Relativity and Quantum Cosmology (gr-qc) Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics General Relativity and Quantum Cosmology Thermodynamics of the universe Mixed dark matter Dark energy Warm dark matter Light dark matter Dark fluid Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Physical Review D. 90 |
| ISSN: | 1550-2368 1550-7998 |
| DOI: | 10.1103/physrevd.90.043015 |
| Popis: | The dark sector of the Universe need not be completely separable into distinct dark matter and dark energy components. We consider a model of early dark energy in which the dark energy mimics a dark matter component in both evolution and perturbations at early times. Barotropic aether dark energy scales as a fixed fraction, possibly greater than one, of the dark matter density and has vanishing sound speed at early times before undergoing a transition. This gives signatures not only in cosmic expansion but in sound speed and inhomogeneities, and in number of effective neutrino species. Model parameters describe the timing, sharpness of the transition, and the relative abundance at early times. Upon comparison with current data, we find viable regimes in which the dark energy behaves like dark matter at early times: for transitions well before recombination the dark energy to dark matter fraction can equal or exceed unity, while for transitions near recombination the ratio can only be a few percent. After the transition, dark energy goes its separate way, ultimately driving cosmic acceleration and approaching a cosmological constant in this scenario. Comment: 10 pages, 8 figures |
| Databáze: | OpenAIRE |
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