Radial excitations of current-carrying vortices
  We report on the existence of a new type of cosmic string solutions in the
Witten model with U(1)xU(1) symmetry. These solutions are superconducting with
radially excited condensates that exist for both gauge and ungauged currents.
Our results suggest that these new configurations can be macroscopically
stable, but microscopically unstable to radial perturbations. Nevertheless,
they might have important consequences for the network evolution and particle
emission. We discuss these effects and their possible signatures. We also
comment on analogies with non-relativistic condensed matter systems where these
solutions may be observable.
