Constraints on the Brans-Dicke gravity theory with the Planck data

Based on the new cosmic microwave background temperature data from the Planck satellite, the nine-year polarization data from the Wilkinson Microwave Anisotropy Probe, and the baryon acoustic oscillation distance ratio data from the Sloan Digital Sky Survey and Six-Degree-Field surveys, we place a new constraint on the Brans-Dicke theory. We adopt a parametrization =ln (1+1), where the general relativity limit corresponds to =0. We find no evidence of deviation from general relativity. At 95% probability, -0. 002460 (i. e. , >0) case, then the 95% probability interval is 181. 65. We can also translate this result to a constraint on the variation of the gravitational constant and find the variation rate today as G=-1. 42-₂. ₂₇^+2. 4810^-13 yr^-1 (1 error bar) ; the integrated change since the epoch of recombination is /G=0. 0104-₀. ₀₀₆₇^+0. 0186 (1 error bar). These limits on the variation of the gravitational constant are comparable with the precision of Solar System experiments.