The objective of this thesis is to study variational methods in the Newtonian N-body
Chapter 1 contains the introduction of Chapters 2 and 3. Chapter 2 is devoted to
the variational proof of the Schubart-like orbits in the collinear four-body problem. In
Chapter 3, we discuss the limiting configurations of the action-minimizing triple collision
orbits in the planar three body problem.