Perturbation theory in Lemaitre-Tolman-Bondi cosmology
- Cosmology and Gravity Group, Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701, Cape Town (South Africa)
- Department of Astrophysics, University of Oxford, Keble Road, Oxford, OX1 3RH (United Kingdom)
The Lemaitre-Tolman-Bondi solution has received much attention as a possible alternative to Dark Energy, as it is able to account for the apparent acceleration of the Universe without any exotic matter content. However, in order to make rigorous comparisons between these models and cosmological observations, such as the integrated Sachs-Wolfe effect, baryon acoustic oscillations and the observed matter power spectrum, it is absolutely necessary to have a proper understanding of the linear perturbation theory about them. Here we present this theory in a fully general, and gauge-invariant form. It is shown that scalar, vector and tensor perturbations interact, and that the natural gauge invariant variables in Lemaitre-Tolman-Bondi cosmology do not correspond straightforwardly to the usual Bardeen variables, in the limit of spatial homogeneity. We therefore construct new variables that reduce to pure scalar, vector and tensor modes in this limit.
- OSTI ID:
- 22273155
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 06 Vol. 2009; ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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