New test of weak equivalence principle using polarized light from astrophysical events Xue-Feng Wu1,2,3∗, Jun-Jie Wei1,4, Mi-Xiang Lan1, He Gao5, Zi-Gao Dai6, and Peter M´esz´aros7,8,9 1 Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008, China 2 School of Astronomy and Space Science, University of Science and Technology of China, Hefei, Anhui 230026, China 3 Joint Center for Particle, Nuclear Physics and Cosmology, Nanjing University-Purple Mountain Observatory, Nanjing 210008, China 4 Guangxi Key Laboratory for Relativistic Astrophysics, Nanning 530004, China 5 Department of Astronomy, Beijing Normal University, Beijing 100875, China 6 School of Astronomy and Space Science, Nanjing University, Nanjing 210093, China 7 Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, Pennsylvania 16802, USA 8 Department of Physics, Pennsylvania State University, 104 Davey Laboratory, University Park, Pennsylvania 16802, USA 9 Center for Particle and Gravitational Astrophysics, Institute for Gravitation and the Cosmos, Pennsylvania State University, 525 Davey Laboratory, University Park, Pennsylvania 16802, USA ∗Electronic address:
[email protected] (Dated: July 5, 2021) Einstein’s weak equivalence principle (WEP) states that any freely falling, uncharged test particle follows the same identical trajectory independent of its internal structure and composition. Since the polarization of a photon is considered to be part of its internal structure, we propose that polarized