Constraining An Exact Brans-Dicke gravity theory with Recent Observations

Understand

In this paper first we study Brans-Dicke equations with the cosmological constant to find an exact solution in the spatially flat Robertson-Walker metric.

• Then we use Observational Hubble data, the baryon acoustic oscillation distance ratio data as well as cosmic microwave background data from Planck to constrain parameters of the obtained Brans-Dicke model.
• To compare our results and find out the amount of deviation from general relativity, we also constrain concordance cosmological model using the same data.
• In our theoretical model the Brans-Dicke coupling constant is replaced by a , say new, parameter namely \textgravedbl scalar field density $\Omega_{\phi}$\textacutedbl.