Ray-tracing and polarized radiative transfer in General Relativity
  We discuss the problem of polarized radiative transfer in general relativity. We present a set of equations suitable for solving the problem numerically for the case of an arbitrary space-time metric, and show numerical solutions to example problems. The solutions are computed with a new ray-tracing code, Arcmancer, developed by the authors. 
Pauli Pihajoki, Antti Rantala, Peter H. Johansson
astro-ph.IM astro-ph.HE gr-qc