Cosmology of a Lorentz violating Galileon theory
Abstract
We modify the scalar Einsteinaether theory by breaking the Lorentz invariance of a gravitational theory coupled to a Galileon type scalar field. This is done by introducing a Lagrange multiplier term into the action, thus ensuring that the gradient of the scalar field is timelike, with unit norm. The theory can also be considered as an extension to the mimetic dark matter theory, by adding some derivative self interactions to the action, which keeps the equation of motion at most second order in time derivatives. The cosmological implications of the model are discussed in detail. In particular, for pressureless baryonic matter, we show that the universe experiences a late time acceleration. The cosmological implications of a special coupling between the scalar field and the trace of the energymomentum tensor are also explored.
 Publication:

Journal of Cosmology and Astroparticle Physics
 Pub Date:
 May 2015
 DOI:
 10.1088/14757516/2015/05/022
 arXiv:
 arXiv:1501.00819
 Bibcode:
 2015JCAP...05..022H
 Keywords:

 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory
 EPrint:
 19 pages, 17 figures