CONICET | Buscador de Institutos y Recursos Humanos

In the last few years, a large number of articles on strong deflection gravitational lensing appeared in the literature. When the lens is a black hole situated between the source and the observer, in addition to the primary and secondary images which correspond to photons with small deflection angles, two infinite sets of relativistic images due to photons that make one or more turns around the deflector are obtained. These relativistic images can be studied numerically or by means of an approximate analytical method called the strong deflection limit. In this talk, the topic of gravitational lensing by black holes is reviewed.