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arXiv · 1611.05447

Inhomogeneous Cosmology with Numerical Relativity

Hayley J. Macpherson·Paul D. Lasky·Daniel J. Price
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Abstract

We perform three-dimensional numerical relativity simulations of homogeneous and inhomogeneous expanding spacetimes, with a view towards quantifying non-linear effects from cosmological inhomogeneities. We demonstrate fourth-order convergence with errors less than one part in 10^6 in evolving a flat, dust Friedmann-Lemaitre-Roberston-Walker (FLRW) spacetime using the Einstein Toolkit within the Cactus framework. We also demonstrate agreement to within one part in 10^3 between the numerical relativity solution and the linear solution for density, velocity and metric perturbations in the Hubble flow over a factor of ~350 change in scale factor (redshift). We simulate the growth of linear perturbations into the non-linear regime, where effects such as gravitational slip and tensor perturbations appear. We therefore show that numerical relativity is a viable tool for investigating nonlinear effects in cosmology.

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Hayley J. Macpherson, Paul D. Lasky, Daniel J. Price. 2016-11-16. Inhomogeneous Cosmology with Numerical Relativity. https://doi.org/10.1103/physrevd.95.064028

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