General relativistic effects on non-linear power spectra

Understand

Non-linear nature of Einstein equation introduces genuine relativistic higher order corrections to the usual Newtonian fluid equations describing the evolution of cosmological perturbations.

• We study the effect of such novel non-linearities on the next-to-leading order matter and velocity power spectra for the case of pressureless, irrotational fluid in a flat Friedmann background.
• We find that pure general relativistic corrections are negligibly small over all scales.
• Our result guarantees that, in the current paradigm of standard cosmology, one can safely use Newtonian cosmology even in non-linear regimes.