We can associate a Newtonian model with purely gravitoelectric
(). Without the gravitomagnetism, the nonlocal nature of
the Newtonian force cannot be retrieved from relativistic models. It
also excludes gravitational waves. The Newtonian model is a limited
model to show the characteristics of the gravitoelectric. We can
also consider an anti-Newtonian model; a model with purely
gravitomagnetic (
). The anti-Newtonian model obstructs
sounding solutions. In Ref. [43], it has been proven that
the anti-Newtonian model shall include either shear or vorticity.