Generalized Brans-Dicke theories

Journal Article · Thu Jul 01 00:00:00 EDT 2010 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2010/07/024· OSTI ID:22272793

De Felice, Antonio; Tsujikawa, Shinji ^[1]

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1. Department of Physics, Faculty of Science, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)

In Brans-Dicke theory a non-linear self interaction of a scalar field φ allows a possibility of realizing the late-time cosmic acceleration, while recovering the General Relativistic behavior at early cosmological epochs. We extend this to more general modified gravitational theories in which a de Sitter solution for dark energy exists without using a field potential. We derive a condition for the stability of the de Sitter point and study the background cosmological dynamics of such theories. We also restrict the allowed region of model parameters from the demand for the avoidance of ghosts and instabilities. A peculiar evolution of the field propagation speed allows us to distinguish those theories from the ΛCDM model.

• OSTI ID: 22272793
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2010, Issue 07; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCELERATION
BRANES
COSMOLOGICAL CONSTANT
COSMOLOGY
DE SITTER GROUP
DE SITTER SPACE
MATHEMATICAL SOLUTIONS
NONLINEAR PROBLEMS
NONLUMINOUS MATTER
POTENTIALS
RELATIVISTIC RANGE
SCALAR FIELDS
STABILITY
VELOCITY