The effect of gravity on light propagation beyond eikonal approximation

The effect of gravity on light propagation beyond eikonal approximation

Gravity interacts with light by, for instance, curving its trajectory or shifting its frequency. These are the well-known gravitational lensing and cosmological redshift effects. However, on the calculation of such effects it is used the eikonal approximation. This models light as a massless particle travelling in ray paths. When we go beyond that approximation, new effects emerge because the extended (wave) nature of light. In this talk, we will discuss how curved spacetimes can couple to polarization of electromagnetic waves, or even modify its propagation to non-null geodesics.