THE N-BODY PROBLEM IN ASTRONOMY

The N body problem is one of the classic problems of Celestial Mechanics whose importance, nowadays, goes beyond the realm of our planetary system. The N body problem plays a central role in the field of dynamics of stellar and galactic systems, as well as in cosmology. The basic algorithm of the N body problem: the description of the dynamical evolution of a physical system that can be represented by discrete elements which are subject to their mutual interaction, is of interest in many branches of physics. In this article we present a review of the role that the N body problem plays in modern astronomy. We describe the main algorithms presently in use, and ilustrate each with examples of current interest in astronomy. We discuss the limits of validity of these numerical algorithms and the dangers in their misuse. Finally, we sketch the future prospects in this field. The author hopes to draw the attention of physicists working in other areas of research who may be interested in applying these algorithms in their work.