Travelling waves in multivortex configurations
  We investigate zero modes of a multivortex background which are due to the energetic degeneracy of the planar static n-vortex solution in Bogomol'nyi limit of the Abelian Higgs model parametrised by a set of 2n real parameters. The zero modes take the form of waves travelling with a speed of light independently along each of the vortices irrespectively to their mutual separations. String description of these zero modes is constructed. We also comment on the remnants of the modes a little outside of the Bogomol'nyi limit. 
Jacek Dziarmaga