Generation of structure on a cosmic-string network

When cosmic strings cross and intercommute, four kinks are created. We calculate the linear density of these kinks, K(t), in an expanding universe. After a period of rapid initial growth, K(t) approaches the scaling K(t)∝${\mathit{t}}^{\mathrm{-}1}$. However, due to the slow decay of kinks, the kink density is orders of magnitude larger than one might expect. Thus, we predict that a single horizon-length segment should have ≊${10}^6$ kinks in the radiation-dominated era. This may explain the lack of scaling behavior in the formation of loops observed in numerical simulations.