Continuous self-similar evaporation of a rotating cosmic string loop
  A solution of the linearized Einstein and Nambu-Goto equations is constructed which describes the evaporation of a certain type of rotating cosmic string - the Allen-Casper-Ottewill loop - under the action of its own self-gravity. The solution evaporates self-similarly, and radiates away all its mass-energy and momentum in a finite time. Furthermore, the corresponding weak-field metric can be matched to a remnant Minkowski spacetime at all points on the future light cone of the final evaporation point of the loop. 
Malcolm Anderson