How to avoid a swift kick in the chameleons

Padilla, Antonio and Platts, Emma and Stefanyszyn, David and Walters, Anthony and Weltman, Amanda and Wilson, Toby (2016) How to avoid a swift kick in the chameleons. Journal of Cosmology and Astroparticle Physics, 2016 . 58/1-58/19. ISSN 1475-7516

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Abstract

Recently, it was argued that the conformal coupling of the chameleon to matter fields created an issue for early universe cosmology. As standard model degrees of freedom become non-relativistic in the early universe, the chameleon is attracted towards a “surfing'' solution, so that it arrives at the potential minimum with too large a velocity. This leads to rapid variations in the chameleon's mass and excitation of high energy modes, casting doubts on the classical treatment at Big Bang Nucleosynthesis. Here we present the DBI chameleon, a consistent high energy modification of the chameleon theory that dynamically renders it weakly coupled to matter during the early universe thereby eliminating the adverse effects of the `kicks'. This is done without any fine tuning of the coupling between the chameleon and matter fields, and retains its screening ability in the solar system. We demonstrate this explicitly with a combination of analytic and numerical results.

Item Type: Article
Keywords: Modified gravity, Big bang nucleosynthesis, Particle physics, Cosmology connection
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Physics and Astronomy
Identification Number: 10.1088/1475-7516/2016/03/058
Depositing User: Padilla, Antonio
Date Deposited: 06 Mar 2017 09:37
Last Modified: 13 Oct 2017 01:34
URI: http://eprints.nottingham.ac.uk/id/eprint/41011

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