Photon interactions with superconducting topological defects
  Using a toy model for the interactions between a defect-forming field and the
photon field where the photon becomes massive in the defect core (motivated by
recent work on defects in the 2HDM), we study the impact on photon propagation
in the background of the defect. We find that, when the photon frequency (in
natural units) is much lower than the symmetry breaking scale, domain walls
reflect most of an incoming photon signal leading to potential interesting
astrophysical signals. We also adapt the calculations for vortices and
monopoles. We find that the case of strings is very similar to the standard
case for massive scalar particles, but in the case of monopoles the
cross-section is proportional to the geometrical area of the monopole.
