... OF RETROGRADE ORBITS3411=m3≤ m2= m, m1= λm, λ ≥ 1, are identical. Theorem 1 applies toregions A1 and A2 in Figure 5. In comparison with Figure 3, this examplecovers triple stars in retrograde ... some t ∈ [0,T]} .EXISTENCE AND MINIMIZING PROPERTIES OF RETROGRADE ORBITS339(a) Given any φ ∈ (0,π], the three-body problem (1) has a retrograde solutionthat minimize the action functional ... used in lunartheory, we call a solution retrograde if its homotopy type in the configurationspace (with collision set removed) is the same as those retrograde orbits inthe lunar theory. Detailed...