Re: [Cosmo-torun] Newtonian N-body wrong in EdS relativistic 2nd order perturbation theory above 10 Mpc

Hi,

http://arxiv.org/abs/1211.0011

Newtonian N-body still valid approach to structure formation sims. even at large scales...

Note the acknowledgements section that suggests that the authors of this paper discussed their results with the authors of the previous paper by Flender and Schwarz.

On Tuesday 10 of July 2012 12:45:52 Boud Roukema wrote:

hi everyone

http://arxiv.org/abs/1207.2035 Newtonian versus relativistic cosmology Authors: Samuel F. Flender, Dominik J. Schwarz

 Abstract: We show how the relativistic matter and velocity power
 spectra behave in different gauges. We construct a new gauge where
 both spectra coincide with Newtonian theory on all
 scales. However, in this gauge there are geometric quantities
 present which do not exist in Newtonian theory, for example the
 local variation of the Hubble parameter. Comparing this quantity
 to second order Newtonian quantities, we find that Newtonian
 theory is wrong on scales larger than 10 Mpc. This undermines the
 reliability of Newtonian cosmological N-body simulations on these
 scales.

What's surprising is that this is still only *perturbation* theory, it's not fully relativistic, if I understand the paper correctly. Fully relativistic calculations still remain to be done.

pozdr boud

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