Constructing perturbation theory kernels for large-scale structure in generalized cosmologies

TL;DR

This paper introduces a numerical method for constructing perturbation theory kernels to analyze large-scale structure in various cosmologies, including modified gravity models, enabling systematic computation of power spectra.

Contribution

A simple numerical scheme for perturbation theory kernel construction applicable to generalized cosmologies where analytic methods are difficult.

Findings

Successfully applied to $f(R)$ gravity and $ ext{Lambda CDM}$ models.

Enables systematic calculation of power spectra and correlation functions.

Facilitates analysis of structure formation in modified gravity scenarios.

Abstract

We present a simple numerical scheme for perturbation theory (PT) calculations of large-scale structure. Solving the evolution equations for perturbations numerically, we construct the PT kernels as building blocks of statistical calculations, from which the power spectrum and/or correlation function can be systematically computed. The scheme is especially applicable to the generalized structure formation including modified gravity, in which the analytic construction of PT kernels is intractable. As an illustration, we show several examples for power spectrum calculations in $f(R)$ gravity and $\Lambda$CDM models.