Cold-dark-matter transfer function
= Cold-dark-matter transfer function
{title2=CDM transfer function}
At fixed time after equality, the comoving cold-dark-matter density contrast per unit primordial curvature grows as $k^2$ for $k\ll k_{\rm eq}$ and only logarithmically for $k\gg k_{\rm eq}$. Small-scale modes entered during radiation domination and could grow only logarithmically until equality.