Periodic orbits in the four body problem with large and small masses

This paper studies the dynamics of the four body problem as a limiting system with two of the masses tending to zero. The relative mass and separation of the two small bodies gives three possible limiting problems, the most interesting of which is called the (2+2)-body problem. Similar limits have been considered by previous authors to study the stability of relative equilibrium. In this paper families of periodic orbits are studied, emanating from relative equilibria and from infinity.