Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-05-24
Int.J.Mod.Phys.D15:2141-2146,2006
Astronomy and Astrophysics
Astrophysics
6 pages, awarded honorable mention in the 2006 Gravity Research Foundation essay competition
Scientific paper
10.1142/S0218271806009728
We discuss the Buchert equations, which describe the average expansion of an inhomogeneous dust universe. In the limit of small perturbations, they reduce to the Friedmann-Robertson-Walker equations. However, when the universe is very inhomogeneous, the behaviour can be qualitatively different from the FRW case. In particular, the average expansion rate can accelerate even though the local expansion rate decelerates everywhere. We clarify the physical meaning of this paradoxical feature with a simple toy model, and demonstrate how acceleration is intimately connected with gravitational collapse. This provides a link to structure formation, which in turn has a preferred time around the era when acceleration has been observed to start.
No associations
LandOfFree
Cosmological acceleration from structure formation 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 Cosmological acceleration from structure formation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cosmological acceleration from structure formation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-72380