Orateur
Description
Black holes accrete and eject matter, giving rise to a complicated spectral signature which rise several open questions (low quiescent luminosity, mechanism supporting the emitted jets). They are known to provide a large reservoir of accessible (rotational) energy allowing to accelerated charged particles at very high energy through various mechanisms. In all these processes, the electromagnetic field supported by the rotating black hole plays a major role. In this talk, I will review the most simple models of magnetospheres around the Kerr black hole. In particular, I will explain how the (hidden) symmetries known as the Killing tower of the Kerr geometry naturally encodes some of the allowed electromagnetic vacuum configurations. In particular, I will review the Carter and the Wald construction to describe the magnetosphere and discuss the property of the non-linear rotating Michel solution. Then, I will discuss the status of the motion of the charged particles in these magnetosphere models. A interesting target is to obtain an analytic form for the acceleration of charged particles, which is possible only under certain circumstances. I will review the condition under which this can be achieved and discuss possible interesting applications to understand the jets structure and high energy emission.
