Contributions from primordial non-Gaussianity and General Relativity to the galaxy power spectrum

TL;DR

This paper calculates how primordial non-Gaussianity and General Relativity influence the galaxy power spectrum, highlighting their detectability and the impact of bias parameters in future large-scale surveys.

Contribution

It provides a comprehensive computation of relativistic and primordial non-Gaussian effects on the galaxy power spectrum, including one-loop terms and bias factors, assessing their observability.

Findings

Relativistic and primordial non-Gaussian effects significantly impact large-scale galaxy clustering.

Certain bias parameter values can mask these effects in observations.

Stage-IV surveys may detect these contributions under specific conditions.

Abstract

We compute the real space galaxy power spectrum, including the leading order effects of General Relativity and primordial non-Gaussianity from the $f_{\mathrm{NL}}$ and $g_{\mathrm{NL}}$ parameters. Such contributions come from the one-loop matter power spectrum terms dominant at large scales, and from the factors of the non-linear bias parameter $b_{\mathrm{NL}}$ (akin to the Newtonian $b_{\phi}$). We assess the detectability of these contributions in Stage-IV surveys. In particular, we note that specific values of the bias parameter may erase the primordial and relativistic contributions to the configuration space power spectrum.