Locally Lorentz-Covariant Theory of Gravity Founded on Inertial Frame of Center of Mass

A locally Lorentz-covariant theory of gravity that is equivalent to general relativity in weak gravitational field is suggested. The space-time standards in local gravitational field are modified in terms of equivalence principle to keep them consistent with those of inertial frame. The static metric in our theory agrees with Schwarzschild metric to the first order approximation. According to our metric expression, black hole and singularity do not exist. The gravitational vector potential generated by a moving body is obtained by applying local Lorentz transformation to Schwarzschild metric in rectangular coordinate system. In our theory, the center of mass of the system is taken as the inertial reference frame. When observed from center of mass, the results of periastron precession and gravitational radiation of binary star system are different from those of general relativity, which are derived from the relative motion of the binary. What's more, the expansion of the universe should also be observed from the center of the universe. By assuming that the Hubble constant varies with different evolution stage of the universe, dark energy is not needed.