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Author Zhao, Xinghai ♦ Mathews, Grant J.
Source arXiv.org
Content type Text
File Format PDF
Date of Submission 2009-12-24
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Natural sciences & mathematics ♦ Astronomy & allied sciences ♦ Physics
Subject Keyword Astrophysics - Cosmology and Nongalactic Astrophysics ♦ General Relativity and Quantum Cosmology ♦ physics:astro-ph ♦ physics:gr-qc
Abstract General relativistic corrections to the expansion rate of the Universe arise when the Einstein equations are averaged over a spatial volume in a locally inhomogeneous cosmology. It has been suggested that they may contribute to the observed cosmic acceleration. In this paper, we propose a new scheme that utilizes numerical simulations to make a realistic estimate of the magnitude of these corrections for general inhomogeneities in (3+1) spacetime. We then quantitatively calculate the volume averaged expansion rate using N-body large-scale structure simulations and compare it with the expansion rate in a standard FRW cosmology. We find that in the weak gravitational field limit, the converged corrections are slightly larger than the previous claimed 10^{-5} level, but not large enough nor even of the correct sign to drive the current cosmic acceleration. Nevertheless, the question of whether the cumulative effect can significantly change the expansion history of the Universe needs to be further investigated with strong-field relativity.
Description Reference: Phys.Rev.D83:023524,2011
Educational Use Research
Learning Resource Type Article
Page Count 13


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