As a test of general relativity on cosmological scales, we measure the \gamma 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 \gamma=0.62+1.8(\sigma_8-0.8) \pm 0.11 at 1-sigma confidence level, which is consistent with the prediction of general relativity, \gamma\simeq0.55\sim0.56. Rather high value of \sigma_8(\geq0.87) is required to be consistent with the prediction of the cosmological DGP model, \gamma\simeq0.68.
@article{arxiv.0805.4789,
title = {Testing general relativity with the multipole spectra of the SDSS luminous red galaxies},
author = {Kazuhiro Yamamoto and Takahiro Sato and Gert Huetsi},
journal= {arXiv preprint arXiv:0805.4789},
year = {2008}
}