When only considering visible baryonic matter,the orbital velocities of stars in the outer regions of galaxies are significantly higher than the predictions of classical gravity and general relativity.This observational anomaly has long been regarded as the core basis for establishing the dark matter hypothesis.Based on the Local Time Freedom Theory,this paper strictly retains all experimentally confirmed conclusions of relativity and quantum mechanics,without modifying the basic equations of gravitational dynamics or introducing any unknown invisible matter particles.It demonstrates that the flattening of galaxy rotation curves is essentially an apparent observational effect caused by the flow rate difference between local proper time and the global coordinate time on Earth,rather than the actual dynamic velocity of celestial bodies exceeding gravitational constraints. The theoretical derivation confirms that the radial matter density gradient of galaxies causes the spacetime coupling strength α to gradually decay with increasing orbital radius,and the local time scaling factor ξ<1.The proper time in regions of weak matter distribution flows slower than the coordinate time in the Earth reference frame, resulting in a systematic amplification of the measured orbital velocities of celestial bodies from the Earth perspective. This paper completes rigorous physical derivation,scale consistency verification,and a clear falsifiable experimental scheme,eliminating the necessity of dark matter existence at the physical principle level.It also uniformly explains tiny motion deviations of celestial bodies inside and outside the Solar System and large-scale cosmic dynamic anomalies.This theory can also serve as a new spacetime research foundation for reconciling core contradictions in quantum gravity.
jingkai cheng (Fri,) studied this question.