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Constraints on scalar-tensor models of dark energy from observational and local gravity tests
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Tsujikawa, Shinji, Uddin, Kotub, Mizuno, Shuntaro, Tavakol, Reza and Yokoyama, Jun’ichi (2008) Constraints on scalar-tensor models of dark energy from observational and local gravity tests. Physical Review D (Particles, Fields, Gravitation and Cosmology), 77 (10). 103009. doi:10.1103/PhysRevD.77.103009 ISSN 1550-7998.
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Official URL: http://dx.doi.org/10.1103/PhysRevD.77.103009
Abstract
We construct a family of viable scalar-tensor models of dark energy (DE) which possess a phase of late-time acceleration preceded by a standard matter era, while at the same time satisfying the local gravity constraints (LGC). The coupling Q between the scalar field and the nonrelativistic matter in the Einstein frame is assumed to be constant in our scenario, which is a generalization of f(R) gravity theories corresponding to the coupling Q=−1/6√. We find that these models can be made compatible with local gravity constraints even when |Q| is of the order of unity through a chameleon mechanism, if the scalar-field potential is chosen to have a sufficiently large mass in the high-curvature regions. We show that these models generally lead to the divergence of the equation of state of DE, which occurs at smaller redshifts as the deviation from the ΛCDM model becomes more significant. We also study the evolution of matter density perturbations and employ them to place bounds on the coupling |Q| as well as model parameters of the field potential from observations of the matter power spectrum and the cosmic microwave background (CMB) anisotropies. We find that, as long as |Q| is smaller than the order of unity, there exist allowed parameter regions that are consistent with both observational and local gravity constraints.
Item Type: | Journal Article | ||||||
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Divisions: | Faculty of Science, Engineering and Medicine > Engineering > WMG (Formerly the Warwick Manufacturing Group) | ||||||
Journal or Publication Title: | Physical Review D (Particles, Fields, Gravitation and Cosmology) | ||||||
Publisher: | American Physical Society | ||||||
ISSN: | 1550-7998 | ||||||
Official Date: | 21 May 2008 | ||||||
Dates: |
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Volume: | 77 | ||||||
Number: | 10 | ||||||
Article Number: | 103009 | ||||||
DOI: | 10.1103/PhysRevD.77.103009 | ||||||
Status: | Peer Reviewed | ||||||
Publication Status: | Published | ||||||
Access rights to Published version: | Restricted or Subscription Access |
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