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

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 oscilla- tion 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 that computed using the best-fitting values for the model parameters. At 68 per cent level of confidence, the combination of Gold sample SNIa, cosmic microwave background (CMB) shift parameter and SDSS data bases provides Ωm = 0.29+0.03-0.02, ΩA = -0.71+0.03-0.03 and μ =-0.40+0.28-0.26, hence a spatially flat Universe with ΩK = 0.00+0.04-0.04. The same combination with SNLS supernova observation gives Ωm = 0.27+0.02-0.02, ΩA =-0.74+0.04-0.02 and μ = 0.00+0.30-0.30 consequently provides a spatially flat Universe ΩK =-0.01+0.04-0.03. These results obviously seem to be compatible with the most recent WMAP results indicating a flat Universe. © 2008 The Authors. Journal compilation © 2008 RAS.