Large Scale Structure Formation of Normal Branch in DGP Brane World Model

TL;DR

This paper investigates the large-scale structure formation in the normal branch of the DGP brane world model, revealing deviations from LCDM and effects on the gravitational potential and ISW effect.

Contribution

It applies the scaling method to analyze perturbations in the normal DGP branch, providing new insights into its structure formation and late-time behavior.

Findings

Detectable departure of gravitational potential from LCDM

Weakening of the integrated Sachs-Wolfe effect

Validity of scaling solution in late-time de Sitter limit

Abstract

In this paper, we study the large scale structure formation of the normal branch in DGP model (Dvail, Gabadadze and Porrati brane world model) by applying the scaling method developed by Sawicki, Song and Hu for solving the coupled perturbed equations of motion of on-brane and off-brane. There is detectable departure of perturbed gravitational potential from LCDM even at the minimal deviation of the effective equation of state w_eff below -1. The modified perturbed gravitational potential weakens the integrated Sachs-Wolfe effect which is strengthened in the self-accelerating branch DGP model. Additionally, we discuss the validity of the scaling solution in the de Sitter limit at late times.