Scalar perturbations in DGP braneworld cosmology

TL;DR

This paper introduces a new numerical method to analyze linear scalar perturbations in DGP braneworld cosmology, providing accurate insights into late-universe density fluctuations without approximations on large scales.

Contribution

A novel numerical approach for solving linear scalar perturbations in DGP cosmology that is valid on large scales and applicable to both branches.

Findings

Effective modeling of late-universe density perturbations.

Validation of the method on large scales.

Insights into differences between self-accelerating and normal branches.

Abstract

We solve for the behaviour of cosmological perturbations in the Dvali-Gabadadze-Porrati (DGP) braneworld model using a new numerical method. Unlike some other approaches in the literature, our method uses no approximations other than linear theory and is valid on large scales. We examine the behaviour of late-universe density perturbations for both the self-accelerating and normal branches of DGP cosmology.