Mesh-refined P 3M: A Fast Adaptive N-Body Algorithm

Substantial improvements in the performance of "particle-particle- particle-mesh" (P^3^M) algorithms may be achieved by allowing spatially adaptive mesh refinements in regions of high particle density. The cycle time under heavy clustering is ~ 5 times that for a uniform particle distribution: ~ 10-20 times faster than conventional P^3^M. The algorithm is roughly 50% faster than a "tree code" while requiring significantly less memory.