Few-body systems

In physics, a few-body system consists of a small number of well-defined structures or point particles.

For some three-body systems an exact solution can be obtained iteratively through the Faddeev equations.

The latter has been solved very precisely using basis sets of Hylleraas or Frankowski-Pekeris functions (see references of the work of G.W.F.

[citation needed] In many cases theory has to resort to approximations to treat few-body systems.

Therefore, any discrepancy found between experiment and theory can be directly related to the theoretical description of few-body effects, or to the existence of new fundamental forces (physics beyond the Standard Model).