Redshift-space distortions
= Redshift-space distortions
{wiki=Redshift-space_distortions}
Redshift-space distortions are the apparent changes in the observed positions and velocities of astronomical objects due to the effects of cosmic expansion and the motion of galaxies within structures such as galaxy clusters. These distortions arise when we observe distant galaxies and characterize their positions using redshift, which refers to the stretching of light from objects that are moving away from us.