Dark energy and non-linear power spectrum

TL;DR

This paper examines how homogeneous dark energy influences the non-linear matter power spectrum in general relativity, revealing a significant deviation from the standard LambdaCDM model on BAO scales.

Contribution

It derives the non-linear power spectrum considering general dark energy effects in a relativistic framework, highlighting observable deviations from LambdaCDM.

Findings

Galaxy power spectrum differs by about 10% from LambdaCDM at BAO scales.

New relativistic contributions affect the linear order density contrast.

Observable signatures of dark energy influence on large-scale structure.

Abstract

We investigate the effects of homogeneous general dark energy on the non-linear matter perturbation in fully general relativistic context. The equation for the density contrast contains even at linear order new contributions which are non-zero for general dark energy. Taking into account the next-leading-order corrections, we derive the total power spectrum in real and redshift spaces. We find that the observable galaxy power spectrum deviates from the LambdaCDM spectrum, which is nearly identical to that in the Einstein-de Sitter universe, and the relative difference is about 10% on a scale of the baryon acoustic oscillations.