Averaged Methods for Vortex-String Evolution
  We discuss friction-dominated vortex-string evolution using a new analytic model recently developed by the authors. By treating the average string velocity, as well as the characteristic lengthscale, as dynamical variables, we can provide a quantitative picture of the complete evolution of a vortex-string network. Previously known scaling laws are confirmed, and new quantitative predictions regarding loop production and evolution are made. 
C. J. A. P. Martins, E. P. S. Shellard (DAMTP, U. Cambridge)