Measuring redshift-space distortions with future SKA surveys

Understand

The peculiar motion of galaxies can be a particularly sensitive probe of gravitational collapse.

• As such, it can be used to measure the dynamics of dark matter and dark energy as well the nature of the gravitational laws at play on cosmological scales.
• Peculiar motions manifest themselves as an overall anisotropy in the measured clustering signal as a function of the angle to the line-of-sight, known as redshift-space distortion (RSD).
• Limiting factors in this measurement include our ability to model non-linear galaxy motions on small scales and the complexities of galaxy bias.