Kinks and small-scale structure on cosmic strings

We discuss some hitherto puzzling features of the small-scale structure of cosmic strings. We argue that kinks play a key role, and that an important quantity to study is their sharpness distribution. In particular we suggest that for very small scales the two-point correlation function of the string tangent vector varies linearly with the separation and not as a fractional power, as proposed by Polchinski and Rocha [Phys. Rev. D 74, 083504 (2006)]. However, our results are consistent with theirs, because the range of scales to which this linearity applies shrinks as evolution proceeds.

Figure 1

Vectors involved in the rate of change of $\mathit{p}·\mathit{q}$.

Figure 2

The initial kink sharpness distribution.

Figure 3

Values of the correlation function $1-z(s,t)$ as a function of $s/t$. Successive curves from right to left are at times $t/t_{*}=1$ (dashed curve), 1.77 (black curve), 2.76 (blue curve), 3.96 (cyan curve), 5.43 (green curve), 7.08 (yellow curve), 8.94 (magenta curve), 10.0 (red curve).