Physical frames along circular orbits in stationary axisymmetric   spacetimes
  Three natural classes of orthonormal frames, namely Frenet-Serret, Fermi-Walker and parallel transported frames, exist along any timelike world line in spacetime. Their relationships are investigated for timelike circular orbits in stationary axisymmetric spacetimes, and illustrated for black hole spacetimes. 
Donato Bini, Christian Cherubini, Andrea Geralico, Robert T. Jantzen
gr-qc