Redshift-space distortions
= Redshift-space distortions
{wiki}
<Redshift-space distortions> arise because observed <galaxy> <redshifts> include <peculiar velocity> as well as <cosmological redshift>. Distances inferred solely from expansion therefore distort clustering along the <line of sight>. Coherent large-scale motion and small-scale <velocity dispersion> produce different effects on the inferred <matter power spectrum>.