Testing general relativity with the multipole spectra of the SPSS luminous red galaxies

As a test of general relativity on cosmological scales, we measure the γ parameter for the growth rate of density perturbations using the redshift-space distortion of the luminous red galaxies in the Sloan Digital Sky Survey (SDSS). Assuming the cosmological constant model, which matches the results of the WMAP experiment, we find γ = 0.62 + 1.8(σ₈ - 0.8) ±0.11 at 1-sigma confidence level, which is consistent with the prediction of general relativity, γ 0.55 ∼ 0.56. Rather high value of σ₈(≥ 0.87) is required to be consistent with the prediction of the cosmological DGP model, γ 0.68.