Periodic solutions with alternating singularities in the collinear four-body problem.

This paper gives an analytic proof of the existence of Schubart-like orbit, a periodic orbit with singularities in the symmetric collinear four-body problem. In each period of the Schubart-like orbit, there is a binary collision (BC) between the inner two bodies and a simultaneous binary collision (SBC) of the two clusters on both sides of the origin. The system is regularized and the existence is proved by using a 'turning point' technique and a continuity argument on differential equations of the regularized Hamiltonian. [ABSTRACT FROM AUTHOR]