Locally Lorentz-Covariant Theory of Gravity Founded on Inertial Frame of   Center of Mass
  A Locally Lorentz-covariant theory of gravity which is equivalent to general relativity in weak gravitational field is present. The space-time standard in local gravitational field is modified in terms of equivalence principle to keep consistent with that of inertial frame. The static metric in our theory agrees with Schwarzschild metric at first order approximation. The gravitational vector potential produced by a moving body is obtained by applying local Lorentz transformations in gravitational field. On the other hand, we still regard inertial frame, i.e. center of mass of the system, as the preferred frame of reference. This is because Newton's laws of motion hold only for inertial frames. The apsidal motion of binary system and the expansion of the universe can be explained reasonably when observed from inertial frame. Black holes and singularities do not exist in our theory. 
Hai-Long Zhao