Cosmic Inhomogeneities and the Average Cosmological Dynamics
arXiv:0806.3497 · doi:10.1103/PhysRevLett.101.181101
Abstract
If general relativity (GR) describes the expansion of the Universe, the observed cosmic acceleration implies the existence of a `dark energy'. However, while the Universe is on average homogeneous on large scales, it is inhomogeneous on smaller scales. While GR governs the dynamics of the \emph{in}homogeneous Universe, the averaged \emph{homogeneous} Universe obeys modified Einstein equations. Can such modifications alone explain the acceleration? For a simple generic model with realistic initial conditions, we show the answer to be `no'. Averaging effects negligibly influence the cosmological dynamics.
5 pages, 2 figures, revtex4; v3 -- Text shortened to match published version. Some typos fixed. No physics changes
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