Cosmic expansion and growth histories in Galileon scalar-tensor models of dark energy

Journal Article · Sat May 15 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.103533· OSTI ID:21409720

Kobayashi, Tsutomu ^[1]

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1. Department of Physics, Waseda University, Okubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan)

We study models of late-time cosmic acceleration in terms of scalar-tensor theories generalized to include a certain class of nonlinear derivative interaction of the scalar field. The nonlinear effect suppresses the scalar-mediated force at short distances to pass solar-system tests of gravity. It is found that the expansion history until today is almost indistinguishable from that of the {Lambda}CDM model or some (phantom) dark energy models, but the fate of the universe depends clearly on the model parameter. The growth index of matter density perturbations is computed to show that its past asymptotic value is given by 9/16, while the value today is as small as 0.4.

• OSTI ID: 21409720
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 10; Other Information: DOI: 10.1103/PhysRevD.81.103533; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMPTOTIC SOLUTIONS
DENSITY
DISTURBANCES
EXPANSION
GRAVITATION
INTERACTIONS
NONLINEAR PROBLEMS
NONLUMINOUS MATTER
PERTURBATION THEORY
SCALAR FIELDS
SOLAR SYSTEM
UNIVERSE
MATHEMATICAL SOLUTIONS
MATTER
PHYSICAL PROPERTIES