The Einstein Equivalence Principle (EEP) can be tested with deflection of light in gravitational field. In this paper, we consider the apparent shifts of active galactic nuclei (AGN) core positions are due to violations of EEP. We use data from multi-wavelength Very Long Baseline Array (VLBA) measurements and the gravitational field from our Milky Way Galaxy to put constraints on the parameterized post-Newtonian (PPN) parameter γ, and the differences of γ for photons over a frequency range of 8.11 to 15.37 GHz are within $2.30\times {10}^{-6}$, while for 1.41 to 15.37 GHz photons are within $5.75\times {10}^{-7}$, considering AGN jet properties. These results provide stringent constraints of EEP over a much wider frequency range than previous analysis.

爱因斯坦等效原理（EEP）可以在重力场中通过光的偏转进行测试。在本文中，我们认为主动银河核（AGN）核心位置的明显变化是由于违反EEP引起的。我们使用来自多波长超长基线阵列（VLBA）测量的数据以及来自银河系的引力场，对参数化后牛顿（PPN）参数γ以及在整个频率范围内光子的γ差进行约束在8.11至15.37 GHz之间$2.30\times {10}^{-6}$，而1.41至15.37 GHz的光子在 $5.75\times {10}^{-7}$，考虑到AGN射流的特性。这些结果在比以前的分析更宽的频率范围内提供了严格的EEP约束。