Gravitational lenses: the strong field limit

Abstract

The project consists in the study of null geodesics in space-times corresponding to black holes, with the fundamental goal of understanding the gravitational lensing phenomena, in their strong field regime. In particular, using the ray tracing technique, it is possible to reconstruct the image of distant objects, as seen by static observers at certain fixed positions, traveling backward along the direction of propagation of light rays with reach the observer. In this way, one can appreciate the deformations of these images due to the presence of the event horizon, which, in principle, could be used to identify a black hole in a direct observation. Ray tracing can be used in both the weak field (small deflection) and strong (large deflections for geodesics approaching the horizon). The main focus of the project is the second case. (AU)