Crossing the cosmological constant line in a dilatonic brane-world model with and without curvature corrections
Abstract
We construct a new brane-world model composed of a bulk with a dilatonic field, plus a brane with brane tension coupled to the dilaton, cold dark matter and an induced gravity term. It is possible to show that, depending on the nature of the coupling between the brane tension and the dilaton, this model can describe the late time acceleration of the brane expansion (for the normal branch) as it moves within the bulk. The acceleration is produced together with a mimicry of the crossing of the cosmological constant line (w = -1) on the brane, although this crossing of the phantom divide is obtained without invoking any phantom matter either on the brane or in the bulk. The role of dark energy is played by the brane tension, which reaches a maximum positive value along the cosmological expansion of the brane. It is precisely at that maximum that the crossing of the phantom divide takes place. We also show that these results remain valid when the induced gravity term on the brane is switched off.
- Publication:
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Journal of Cosmology and Astroparticle Physics
- Pub Date:
- October 2008
- DOI:
- 10.1088/1475-7516/2008/10/011
- arXiv:
- arXiv:0807.4678
- Bibcode:
- 2008JCAP...10..011B
- Keywords:
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- High Energy Physics - Theory;
- Astrophysics;
- General Relativity and Quantum Cosmology
- E-Print:
- 12 pages, 2 figures, RevTeX 4