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Dark D-brane cosmology

Tomi Koivisto, Danielle Wills, Ivonne Zavala, Ivonne Zavala Carrasco Orcid Logo

Journal of Cosmology and Astroparticle Physics, Volume: 2014, Issue: 06, Pages: 036 - 036

Swansea University Author: Ivonne Zavala Carrasco Orcid Logo

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Abstract

Disformally coupled cosmologies arise from Dirac-Born-Infeld actions in Type II string theories, when matter resides on a moving hidden sector D-brane. Since such matter interacts only very weakly with the standard model particles, this scenario can provide a natural origin for the dark sector of th...

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Published in: Journal of Cosmology and Astroparticle Physics
ISSN: 1475-7516
Published: 2014
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa21633
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Abstract: Disformally coupled cosmologies arise from Dirac-Born-Infeld actions in Type II string theories, when matter resides on a moving hidden sector D-brane. Since such matter interacts only very weakly with the standard model particles, this scenario can provide a natural origin for the dark sector of the universe with a clear geometrical interpretation: dark energy is identified with the scalar field associated to the D-brane's position as it moves in the internal space, acting as quintessence, while dark matter is identified with the matter living on the D-brane, which can be modelled by a perfect fluid. The coupling functions are determined by the (warped) extra-dimensional geometry, and are thus constrained by the theory. The resulting cosmologies are studied using both dynamical system analysis and numerics. From the dynamical system point of view, one free parameter controls the cosmological dynamics, given by the ratio of the warp factor and the potential energy scales. The disformal coupling allows for new scaling solutions that can describe accelerating cosmologies alleviating the coincidence problem of dark energy. In addition, this scenario may ameliorate the fine-tuning problem of dark energy, whose small value may be attained dynamically, without requiring the mass of the dark energy field to be unnaturally low.
College: College of Science
Issue: 06
Start Page: 036
End Page: 036