This project will create a Theoretical and Computational Astrophysics Network with major nodes at the University of Illinois at Urbana-Champaign, the University of California at Berkeley, and Princeton University, to advance the theory of black hole accretion and outflows. Accretion of matter onto black holes is central to many astrophysical and gravitational phenomena, but current theory lacks self-consistent models both for high accretion rate flows where radiation forces are important, and for low accretion rate flows where collisionless plasma effects are important. The network team brings together expertise in high performance computing techniques, astrophysics, and plasma physics in order to address this need. The team will develop a general relativistic, radiation magnetohydrodynamics code to study luminous accreting black holes, and a multi-fluid relativistic magnetohydrodynamics code with anisotropic electron and ion pressures, conduction, viscosity, and radiative heating and cooling to study slowly accreting systems. These new codes will be used to address fundamental questions about the structure and observational appearance of the inner accretion disk as well as the origin and maintenance of the large-scale magnetic fields believed to power relativistic jets, and then will be made publicly available to the research community. The network will contribute to scientific workforce development by supporting the work of undergraduate students, graduate students, and postdocs; and a program of visualizations, released on the internet, will help communicate the excitement of black hole astrophysics to the scientific community and to the broader public.
