Does accelerating universe indicate Brans-Dicke theory?
Department of Physics, Liaoning Normal University, 116029, Dalian, China
2 Korea Astronomy and Space Science Institute, 305-348, Daejon, Korea
3 School of Physics and Optoelectronic Technology, Dalian University of Technology, 116024, Dalian, China
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Revised: 3 September 2011
Accepted: 21 September 2011
Published online: 17 October 2011
The evolution of the universe in Brans-Dicke (BD) theory is discussed in this paper. Considering a parameterized scenario for BD scalar field φ = φ 0 a α which plays the role of gravitational constant G, we apply the Markov Chain Monte Carlo method to investigate a global constraints on BD theory with a self-interacting potential according to the current observational data: the Union2 dataset of type-Ia supernovae (SNIa), the high-redshift Gamma-Ray Bursts (GRBs) data, the observational Hubble data (OHD), the cluster X-ray gas mass fraction, the baryon acoustic oscillation (BAO), and the cosmic microwave background (CMB) data. It is shown that an expanded universe from deceleration to acceleration is given in this theory, and the constraint results of dimensionless matter density Ω 0m and parameter α are, Ω 0m = 0.286 −0.039−0.047 +0.037+0.050 and α = 0.0046 −0.0171−0.0206 +0.0149+0.0171 which is consistent with the result of current experiment exploration, |α| ≤ 0.132124. In addition, we use the geometrical diagnostic method, jerk parameter j, to distinguish the BD theory and the cosmological constant model in Einstein’s theory of general relativity.
© Società Italiana di Fisica and Springer-Verlag Berlin Heidelberg, 2011