Modifying gravity at low redshift

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

DOI:https://doi.org/10.1088/1475-7516/2010/04/032· OSTI ID:22272866

Brax, Philippe ^[1]; Bruck, Carsten van de ^[2]; Davis, Anne-Christine ^[3]; Shaw, Douglas ^[4]

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1. Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France)
2. Department of Applied Mathematics, University of Sheffield Hounsfield Road, Sheffield S3 7RH (United Kingdom)
3. Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, Cambridge CB3 0WA (United Kingdom)
4. Queen Mary University of London, Astronomy Unit, Mile End Road, London E1 4NS (United Kingdom)

We consider the growth of cosmological perturbations in modified gravity models where a scalar field mediates a non-universal Yukawa force between different matter species. The growth of the density contrast is altered for scales below the Compton wave-length of the scalar field. As the universe expands, the Compton wave-length varies in time in such a way that scales which were outside the range of the scalar field force may feel it at a lower redshift. In this case, both the exponent γ measuring the growth of Cold Dark Matter perturbations and the slip function representing the ratio of the two Newtonian potentials ψ and φ may differ from their values in General Relativity at low redshift.

• OSTI ID: 22272866
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2010, Issue 04; 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
ASTROPHYSICS
COSMOLOGY
DISTURBANCES
GENERAL RELATIVITY THEORY
GRAVITATION
NONLUMINOUS MATTER
POTENTIALS
RED SHIFT
SCALAR FIELDS
UNIVERSE