Shadow and Polarized Images of Schwarzschild-MOG Black Hole Illuminated by Thick Accretion Disk
gr-qc, astro-ph.HE, hep-th
Submitted: 2026-09-16
Updated: 2026-09-16
Comments: 32 pages, 9 figures
License: http://creativecommons.org/licenses/by-nc-sa/4.0/
The gist: Recent EHT polarimetric observations provide a powerful probe of near-horizon physics and modified gravity.
Terminology
Abstract
Recent EHT polarimetric observations provide a powerful probe of near-horizon physics and modified gravity. We investigate the shadow and polarization images of a static Schwarzschild-MOG black hole illuminated by geometrically thick, optically thin accretion flows. Adopting a phenomenological model and the Hou disk model, and solving null geodesics and relativistic radiative transfer, we study how the MOG parameter, inclination angle, anisotropic synchrotron emission, and flow geometry affect the total intensity and linear polarization. It is found that the MOG parameter mainly enlarges and brightens higher-order photon rings and broadens the shadow, while the inclination angle breaks axial symmetry and enhances polarized emission inside the shadow. The Hou disk model suppresses off-equatorial radiative interference and localizes polarization signals within higher-order rings. Electric vector position angle (EVPA) patterns are mostly azimuthal but vary rapidly near lensed images. These results provide theoretical diagnostics for constraining MOG with EHT/ngEHT polarimetric observations.
Sources
Related papers
- Listening to the Horizon: Probing Near-Horizon Reflectivity with GW250114
- A Pairwise Surrogate for Gravitational-Wave Spectra from Highly Relativistic Vacuum Bubble Collisions
- Tests of General Relativity with Einstein Telescope
- A weakly modelled view of the joint compact-binary mass plane: population structure and spectral-siren cosmology
- Unitary quantum matter-bounce in a universe with a positive cosmological constant
- Nonreciprocal black holes with primary hair in beyond Horndeski gravity: Exact solutions and stability