This award supports a computational study of astrophysical jets. An astrophysical jet is a high-speed, highly collimated stream of ionized gas, a plasma, that emanates from astronomical objects such as supermassive black holes in the heart of vast galaxies. These jets can travel over great distances in space and are powered by the intense magnetic fields associated with the astronomical object they originate from. The high relativistic velocity and energy of these astrophysical jets make them important features of the astrophysical landscape, as they can carry large amounts of energy and matter but also accelerate particles to the highest energies known. Studying astrophysical relativistic jets by complementing observations with supercomputer simulations enables understanding of the physical processes that drive these extremely energetic phenomena. It also allows to better understand the role they play in shaping the evolution of vast galaxies and other mysterious astronomical objects. <br/> <br/>With the help of the supercomputer facilities of the Texas Advanced Computing Center, this project will use an innovative technique to perform large-scale, kinetic plasma three-dimensional Particle-in-Cell (PIC) simulations of relativistic jets, applicable to the black hole jet environments. In particular, the project will investigate the role of kinetic instabilities to understand the important acceleration mechanism, shocks and magnetic reconnection, in simulated cylindrical jets with helical magnetic fields. This study will advance our knowledge of these highly energetic phenomena, which cannot currently be investigated using the traditional single-fluid relativistic magnetohydrodynamic simulations. By performing a study of high energy particle acceleration mechanisms within electromagnetically observed sources, this project addresses goals of NSF's "Windows on the Universe: The Era of Multi-Messenger Astrophysics" program.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.