Spatial dispersion of light rays propagating through a plasma in Kerr space-time

Kimpson. T, Wu. K, Zane. S

[arXiv:1901.03733] [doi:10.1093/mnras/stz138]

We investigate the propagation of light through a plasma on a background Kerr space-time via a Hamiltonian formulation. The behaviour of light when propagating through a vacuum and through a plasma is not the same; the convolution of gravitational and plasma effects gives rise to a dispersion in both space and time. The magnitude of the dispersion is a strong function of both the ray frequency and impact parameter. We discuss implications for the detection of gravitationally bent pulsar beams near the Galactic centre