Observational constraints on the braneworld model with brane-bulk energy exchange

TL;DR

This paper tests a braneworld cosmological model with energy exchange between brane and bulk against recent observational data, finding it consistent with a flat universe and dark energy-like behavior.

Contribution

It provides observational constraints on a braneworld model with brane-bulk energy exchange, demonstrating its compatibility with current cosmological data and the flatness of the universe.

Findings

Model behaves like dark energy affecting cosmic expansion

Results support a flat universe with specific parameter values

Compatible with WMAP observations

Abstract

We investigate the viability of the braneworld model with energy exchange between the brane and bulk, by using the most recent observational data related to the background evolution. We show that this energy exchange behaves like a source of dark energy and can alter the profile of the cosmic expansion. The new Supernova Type Ia (SNIa) Gold sample, Supernova Legacy Survey (SNLS) data, the position of the acoustic peak at the last scattering surface from the Wilkinson Microwave Anisotropy Probe (WMAP) observations and the baryon acoustic oscillation peak found in the Sloan Digital Sky Survey (SDSS) are used to constrain the free parameters of this model. To infer its consistency with the age of the Universe, we compare the age of old cosmological objects with what computed using the best fit values for the model parameters. At 68% level of confidence, the combination of Gold sample SNIa, Cosmic Microwave Background (CMB) shift parameter and SDSS databases provide $\Omega_m=0.29_{-0.02}^{+0.03}$, $\Omega_{A}=-0.71_{-0.03}^{+0.03}$ and $\mu=-0.40_{-0.26}^{+0.28}$, hence a spatially flat Universe with $\Omega_K=0.00_{-0.04}^{+0.04}$. The same combination with SNLS supernova observation give $\Omega_m=0.27_{-0.02}^{+0.02}$, $\Omega_{A}=-0.74_{-0.02}^{+0.04}$ and $\mu=0.00_{-0.30}^{+0.30}$ consequently provides a spatially flat Universe $\Omega_K=-0.01_{-0.03}^{+0.04}$. These results obviously seem to be compatible with the most recent WMAP results indicating a flat Universe.