Testing General Relativity with Growth rate measurement from Sloan Digital Sky Survey III Baryon Oscillations Spectroscopic Survey galaxies

Understand

The measured redshift ($z$) of an astronomical object is a combination of Hubble recession, gravitational redshift and peculiar velocity.

• The line of sight distance to a galaxy inferred from redshift is affected by the peculiar velocity component of galaxy redshift, which is observed as an anisotropy in the correlation function.
• This anisotropy allows us to measure the linear growth rate of matter ($f\sigma_8$).
• We measure the $f\sigma_8$ at $z=0.57$ using the CMASS sample from Data Release 11 of Sloan Digital Sky Survey III (SDSS III) Baryon Oscillations Spectroscopic Survey (BOSS).