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

[Boud Roukema]

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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