Pulsar Polarization Array Limits on Ultralight Axionlike Dark Matter

Author(s): Xiao Xue, Shi Dai, Hoang Nhan Luu, Tao Liu, Jing Ren, Jing Shu, Yue Zhao, Andrew Zic, N. D. Ramesh Bhat, Zu-Cheng Chen, Yi Feng, George Hobbs, Agastya Kapur, Richard N. Manchester, Rami Mandow, Saurav Mishra, Daniel J. Reardon, Christopher J. Russell, Ryan M. Shannon, Shuangqiang Wang, Lei Zhang, Songbo Zhang, and Xingjiang Zhu (PPTA Collaboration) By cross-correlating pulsar polarization data within the galaxy, the PPTA collaboration sets the most sensitive limits on how strongly “Fuzzy” axionlike dark matter can interact with Chern-Simons coupling. [Phys. Rev. Lett. 136, 011001] Published Wed Jan 07, 2026