 Fast multipole method

The Fast Multipole Method (FMM) is a numerical technique used to speed up the computation of interactions in systems with many particles, such as in simulations of gravitational, electrostatic, or other types of forces. The method was first introduced by Leslie Greengard and Vladimir Rokhlin in the late 1980s. ### Key Concepts of the Fast Multipole Method: 1. **Problem Context**: When simulating N-body problems (e.g.