Astronomy and Astrophysics – Astrophysics – General Relativity and Quantum Cosmology
Scientific paper
2011-09-07
Astronomy and Astrophysics
Astrophysics
General Relativity and Quantum Cosmology
37 pages
Scientific paper
In classical gravity deviations from the predictions of the Einstein theory are often discussed within the framework of the conformal Newtonian gauge, where scalar perturbations are described by two potentials $\phi$ and $\psi$. In this paper we use the above gauge to explore possible cosmological consequences of a running Newton's constant $ G (\Box) $, as suggested by the nontrivial ultraviolet fixed point scenario arising from the quantum field-theoretic treatment of Einstein gravity with a cosmological constant term. Here we focus on the effects of a scale-dependent coupling on the so-called gravitational slip functions $\eta = \psi / \phi -1 $, whose classical general relativity value is zero. Starting from a set of manifestly covariant but non-local effective field equations derived earlier, we compute the leading corrections in the potentials $\phi$ and $\psi$ for a nonrelativistic, pressureless fluid. After providing an estimate for the quantity $\eta$, we then focus on a comparison with results obtained in a previous paper on matter density perturbations in the synchronous gauge, which gave an estimate for the growth index parameter $\gamma$, also in the presence of a running $G$. Our results indicate that, in the present framework and for a given $ G (\Box) $, the corrections tend to be significantly larger in magnitude for the perturbation growth exponents than for the conformal Newtonian gauge slip function.
Hamber Herbert W.
Toriumi Reiko
No associations
LandOfFree
Scale-Dependent Newton's Constant G in the Conformal Newtonian Gauge does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Scale-Dependent Newton's Constant G in the Conformal Newtonian Gauge, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Scale-Dependent Newton's Constant G in the Conformal Newtonian Gauge will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-306251