Cosmic Jerk, Snap and Beyond
General Relativity and Quantum Cosmology
2008-12-18 v2 Astrophysics
High Energy Physics - Theory
Abstract
We clarify the procedure for expressing the Friedmann equation in terms of directly measurable cosmological scalars constructed out of higher derivatives of the scale factor. We carry out this procedure for pure dust, Chaplygin gas and generalised Chaplygin gas energy-momentum tensors. In each case it leads to a constraint on the scalars thus giving rise to a test of General Relativity. We also discuss a formulation of the Friedmann equation as unparametrised geodesic motion and its connection with the Lagrangian treatment of perfect fluids coupled to gravity.
Cite
@article{arxiv.0807.0207,
title = {Cosmic Jerk, Snap and Beyond},
author = {Maciej Dunajski and Gary Gibbons},
journal= {arXiv preprint arXiv:0807.0207},
year = {2008}
}
Comments
10 pages. Minor revisions, added summary. Final version to appear in CQG