Distinguishing modified gravity models

Journal Article · Thu Oct 01 04:00:00 EDT 2015 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2015/10/042· OSTI ID:22525236

Brax, Philippe ^[1]; Davis, Anne-Christine ^[2]

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1. Institut de Physique Théorique, Université Paris-Saclay, CEA, CNRS, F-91191 Gif/Yvette Cedex (France)
2. DAMTP, Centre for Mathematical Sciences, University of Cambridge, Cambridge, CB3 0WA (United Kingdom)

Modified gravity models with screening in local environments appear in three different guises: chameleon, K-mouflage and Vainshtein mechanisms. We propose to look for differences between these classes of models by considering cosmological observations at low redshift. In particular, we analyse the redshift dependence of the fine structure constant and the proton to electron mass ratio in each of these scenarios. When the absorption lines belong to unscreened regions of space such as dwarf galaxies, a time variation would be present for chameleons. For both K-mouflage and Vainshtein mechanisms, the cosmological time variation of the scalar field is not suppressed in both unscreened and screened environments, therefore enhancing the variation of constants and their detection prospect. We also consider the time variation of the redshift of distant objects using their spectrocopic velocities. We find that models of the K-mouflage and Vainshtein types have very different spectroscopic velocities as a function of redshift and that their differences with the Λ-CDM template should be within reach of the future ELT-HIRES observations.

• OSTI ID: 22525236
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 10 Vol. 2015; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
COSMOLOGICAL CONSTANT
COSMOLOGY
ELECTRONS
FINE STRUCTURE
GALAXIES
GRAVITATION
MASS
NONLUMINOUS MATTER
PROTONS
RED SHIFT
SCALAR FIELDS
SPACE
VARIATIONS
VELOCITY