Black Hole Accretion Flows and Relativistic Jets: Physics and Simulations

Active Glactic Nuclei (AGNs) are believed to be powered by accretion onto supermassive black holes. It has become increasingly accepted that magnetic fields play a vital role in accretion and subsequent launching of relativistic jets. The driving mechanism behind accretion is the magnetohydrodynamical process and associated stresses; jets are most likely launched from Blandford-Znajek process in which magnetic fields help to extract rotational energy of the hole. Local and global black hole accretion simulations have revealed the detailed physics behind accretion and the intimate connections between accretion and jets. In this talk I will review the issues involved, recent progress in simulations, and the remaining challenges.