Observational Constraints on the Normal Branch of a Warped DGP Cosmology

TL;DR

This paper uses multiple observational datasets to constrain the parameters of the warped DGP braneworld cosmology, revealing a phantom-like effective behavior and estimating the universe's age.

Contribution

It provides new observational constraints on the normal branch of warped DGP cosmology using combined data, and analyzes its effective cosmological dynamics.

Findings

Best fit matter density: Ω_m ≈ 0.22-0.24

Effective equation of state indicates phantom-like behavior

Estimated universe age consistent with observations

Abstract

We investigate observational constraints on the normal branch of the warped DGP braneworld cosmology by using observational data from Type Ia Supernovae (SNIa), Baryon Acoustic Oscillations (BAO), Cosmic Microwave Background (CMB) and Baryon Gas Mass Fraction of cluster of galaxies. The best fit values of model free parameters are: $\Omega_m=0.240^{+0.050}_{-0.130}$ and $\Omega_{r_c}=0.000^{+0.014}$ at $1\sigma$ confidence interval by using Gold sample SNIa+CMB shift parameter+BAO+Gas mass fraction of baryons in cluster of galaxies. The results for essence sample SNIa combined with CMB shift parameter, BAO and Baryon Gas mass fraction correspont to: $\Omega_m= 0.220^{+0.020}_{-0.170}$ and $\Omega_{r_c}=0.000^{+0.025}$ at 68.3% confidence interval. We determine the age of the universe by using these best fit values. We also study the effective cosmological dynamics on the brane via an effective equation of state parameter and the deceleration parameter to conclude that an effective phantom-like behavior arises in this scenario.