Two body problem on two point homogeneous spaces, invariant differential   operators and the mass center concept
  We consider the two body problem with central interaction on two point homogeneous spaces from point of view of the invariant differential operators theory. The representation of the two particle Hamiltonian in terms of the radial differential operator and invariant operators on the symmetry group is found. The connection of different mass center definitions for these spaces to the obtained expression for Hamiltonian operator is studied. 
Alexey V. Shchepetilov (Moscow State University)