A Perturbative Approach to the Redshift Space Power Spectrum: Beyond the Standard Model

TL;DR

This paper presents a perturbative method and code for calculating the redshift space power spectrum in modified gravity and dark energy models, enabling better modeling of non-linear effects and anisotropies for upcoming high-precision data.

Contribution

It introduces a flexible code based on standard perturbation theory for diverse gravity models, extending non-linear modeling of the redshift space power spectrum.

Findings

Code accurately models anisotropy at relevant scales.

Captures non-linear effects in modified gravity theories.

Validated against established results.

Abstract

We develop a code to produce the power spectrum in redshift space based on standard perturbation theory (SPT) at 1-loop order. The code can be applied to a wide range of modified gravity and dark energy models using a recently proposed numerical method by A.Taruya. This includes Horndeski's theory with a general potential, which accommodates both chameleon and Vainshtein screening mechanisms and provides a non-linear extension of the effective theory of dark energy up to third order. Focus is on a recent non-linear model of the redshift space power spectrum which has been shown to model the anisotropy very well at relevant scales for the SPT framework, as well as capturing relevant non-linear effects typical of modified gravity theories. We provide consistency checks of the code against established results and elucidate it's application within the light of upcoming high precision RSD data.