Dynamics of non-minimally coupled perfect fluids
Abstract
We present a general formulation of the theory for a non-minimally coupled perfect fluid in which both conformal and disformal couplings are present. We discuss how such non-minimal coupling is compatible with the assumptions of a perfect fluid and derive both the Einstein and the fluid equations for such model. We found that, while the Euler equation is significantly modified with the introduction of an extra force related to the local gradients of the curvature, the continuity equation is unaltered, thus allowing for the definition of conserved quantities along the fluid flow. As an application to cosmology and astrophysics we compute the effects of the non-minimal coupling on a Friedmann--Lema\^itre--Robertson--Walker metric at both background and linear perturbation level and on the Newtonian limit of our theory.
Keywords
Cite
@article{arxiv.1502.06613,
title = {Dynamics of non-minimally coupled perfect fluids},
author = {Dario Bettoni and Stefano Liberati},
journal= {arXiv preprint arXiv:1502.06613},
year = {2015}
}
Comments
26 pages, 2 appendix, no figures. Revised version: new sections discussing the absence of extra degrees of freedom and the cosmological linear perturbations. Published in JCAP