Polarized image of a synchrotron-emitting ring in an Einstein-Maxwell-scalar theory
Phys. Rev. D 112, 024044 – Published 18 July, 2025
DOI: https://doi.org/10.1103/kbkh-xgp7
Abstract
This study investigates polarized images of an equatorial synchrotron-emitting ring surrounding hairy black holes within the Einstein-Maxwell-scalar theory. Our analysis demonstrates qualitative similarities between the polarization patterns of hairy black holes and Schwarzschild black holes. However, due to the nonminimal coupling between the scalar and electromagnetic fields, an increase in black hole charge and coupling constant can substantially amplify polarization intensity and induce deviations in the electric vector position angle. These effects may offer observational signatures to distinguish hairy black holes from Schwarzschild black holes.
