An Etymological Dictionary of Astronomy and Astrophysics

Reduced growth or stagnation undergone by → cold dark matter perturbations during the period when the → early Universe was → radiation-dominated. The photons cannot collapse, and by their pressure prevent the matter to do so, when radiation dominates. Matter pertubation (collapse) remains frozen until the density equality between radiation and matter.

See also: Péter Mészáros, 1974, A&A 37, 225; → effect.