Force-Free Magnetohydrodynamics Near Kerr Black Holes

Abstract

Some galaxies emit incredibly strong jets of radiation. The source of this radiation is projected to be a supermassive, spinning black hole at the center of the galaxy; in particular, the plasma that surrounds the black hole may interact with the horizon of the hole in such a way that it is able to extract some of the rotational energy from the hole through Poynting fluxes and angular momentum fluxes. The mathematics of this process is complicated, and the goal of this thesis is to find a way of evaluating it and of understanding physically what it says about the nature of energy extraction from the black hole. To do this, the thesis develops a Lagrangian machinery to analyze the plasma around the black hole and demonstrates some combinations of fields that may appear around the black hole in the region very close to the horizon of the hole. These fields obey the same symmetries as the space around the black hole and may lead to interesting energy extraction from the black hole.