Probing Axion Clouds with EHT Data Using Closure Trace Analyses

May 04, 2026 PIRSA:26050052 Scientific Series Other

Wang, Z. (2026). Probing Axion Clouds with EHT Data Using Closure Trace Analyses. Perimeter Institute. https://pirsa.org/26050052

Wang, Zhiren. Probing Axion Clouds with EHT Data Using Closure Trace Analyses. Perimeter Institute, May. 04, 2026, https://pirsa.org/26050052

@misc{ pirsa_PIRSA:26050052,
  doi = {10.48660/26050052},
  url = {https://pirsa.org/26050052},
  author = {Wang, Zhiren},
  keywords = {Other},
  language = {en},
  title = {Probing Axion Clouds with EHT Data Using Closure Trace Analyses},
  publisher = {Perimeter Institute},
  year = {2026},
  month = {may},
  note = {PIRSA:26050052 see, \url{https://pirsa.org}}
}

Abstract

Axion-like particles can form clouds around rotating supermassive black holes through superradiant instability. Via axion-photon coupling, these clouds can imprint time-dependent oscillations on the observed electric vector position angle. I will present constraints on such clouds around M87* and Sgr A* using 2017 Event Horizon Telescope polarimetric data. The analysis is based on conjugate closure trace products, which are non-imaging and insensitive to dominant calibration systematics such as station gains and polarization leakage. I will highlight the contrast between the relatively stable M87* data and the highly variable Sgr A* case, and discuss the prospects of applying this pipeline to future EHT and more sensitive next-generation EHT observations.