On the Growth of Perturbations as a Test of Dark Energy

Details On the Growth of Perturbations as a Test of Dark Energy On the Growth of Perturbations as a Test of Dark Energy

2006-04-23

arxiv.org/abs/astro-ph/0604485v3

Astrophys.J.648:797-806,2006

Astronomy and Astrophysics

Astrophysics

25 pages, 1 figure, submitted to ApJ; references added; expanded discussion of entropy perturbations, initial-value constraint

Scientific paper

10.1086/506021

The strongest evidence for dark energy comes presently from geometric techniques such as the supernova distance-redshift relation. By combining the measured expansion history with the Friedmann equation one determines the energy density and its time evolution, hence the equation of state of dark energy. Because these methods rely on the Friedmann equation which has not been independently tested it is desirable to find alternative methods that work for both general relativity and other theories of gravity. Assuming that sufficiently large patches of a perturbed Robertson-Walker spacetime evolve like separate Robertson-Walker universes, that shear stress is unimportant on large scales and that energy and momentum are locally conserved, we derive several relations between long-wavelength metric and matter perturbations. These relations include generalizations of the initial-value constraints of general relativity. For a class of theories including general relativity we reduce the long-wavelength metric, density, and velocity potential perturbations to quadratures including curvature perturbations, entropy perturbations, and the effects of nonzero background curvature. When combined with the expansion history measured geometrically, the long-wavelength solution provide a test that may distinguish modified gravity from other explanations of dark energy.

Affiliated with

Also associated with

No associations

Rating

On the Growth of Perturbations as a Test of Dark Energy 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 On the Growth of Perturbations as a Test of Dark Energy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the Growth of Perturbations as a Test of Dark Energy will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-120658