Photon deflection and precession of the periastron in terms of spatial   gravitational fields
  We show that a Maxwell-like system of equations for spatial gravitational fields $\bf g$ and $\bf B$ (latter being the analogy of a magnetic field), modified to include an extra term for the $\bf B$ field in the expression for force, leads to the correct values for the photon deflection angle and for the precession of the periastron. 
W. D. Flanders and G. S. Japaridze