A PARALLEL SELF-CONSISTENT-FIELD CODE

We describe a version of an algorithm for evolving self-gravitating co llections of particles that should be nearly ideal for parallel archit ectures. Our method is derived from the ''self-consistent field'' (SCF ) approach suggested previously by Clutton-Brock and others. Owing to the use of a global description of the gravitational held, the particl es in an SCF simulation do not interact with one another directly, min imizing communications overhead between nodes in a parallel implementa tion. Ideal load balancing is achieved since precisely the same number of operations are needed to compute the acceleration for each particl e. Consequently, the SCF technique is perfectly scalable and the size of feasible applications will grow in simple proportion to advances in computational hardware. We describe an SCF code developed for and tes ted on a Connection Machine 5. Empirical tests demonstrate the efficie nt and scalable nature of the algorithm. Depending on the application, simulations with particle numbers in the range N similar to 10(7)-10( 8.5) are now possible. Larger platforms should make simulations with b illions of particles feasible in the near future. Specific astrophysic al applications are discussed in the context of collisionless dynamics .