Kepler Equation for the Compact Binaries under the Spin-spin Interaction
  In this work we consider compact binaries on eccentric orbit under the spin-spin interaction. Using the post-Newtonian formalism, the binaries undergo a perturbed Keplerian motion. Here we investigate only the radial motion and derive the contribution of the second post-Newtonian order spin-spin effect to the solution. 
Zolt\'an Keresztes, Bal\'azs Mik\'oczi