Cosmic Constraint to DGP Brane Model: Geometrical and Dynamical Perspectives

TL;DR

This study tests the DGP brane model against current cosmological data, finding strong evidence that the flat Lambda-CDM model fits observations significantly better than the DGP model from both geometrical and dynamical perspectives.

Contribution

It provides a comprehensive observational constraint on the DGP brane model using multiple cosmological data sets, comparing its viability against the standard Lambda-CDM model.

Findings

Flat Lambda-CDM model is favored over DGP by over 4-6 sigma.

Current data strongly disfavors the DGP model as an alternative to dark energy.

Growth function data are consistent with the geometrical constraints.

Abstract

In this paper, the Dvali-Gabadadze-Porrati (DGP) brane model is confronted by current cosmic observational data sets from geometrical and dynamical perspectives. On the geometrical side, the recent released Union2 $557$ of type Ia supernovae (SN Ia), the baryon acoustic oscillation (BAO) from Sloan Digital Sky Survey and the Two Degree Galaxy Redshift Survey (transverse and radial to line-of-sight data points), the cosmic microwave background (CMB) measurement given by the seven-year Wilkinson Microwave Anisotropy Probe observations (shift parameters $R$, $l_a(z_\ast)$ and redshift at the last scatter surface $z_\ast$), ages of high redshifts galaxies, i.e. the lookback time (LT) and the high redshift Gamma Ray Bursts (GRBs) are used. On the dynamical side, data points about the growth function (GF) of matter linear perturbations are used. Using the same data sets combination, we also constrain the flat $\Lambda$CDM model as a comparison. The results show that current geometrical and dynamical observational data sets much favor flat $\Lambda$CDM model and the departure from it is above $4\sigma$($6\sigma$) for spatially flat DGP model with(without) SN systematic errors. The consistence of growth function data points is checked in terms of relative departure of redshift-distance relation.