Testing black hole equatorial reflection symmetry using Sgr A* shadow images

Abstract

The recently released images of the supermassive black holes in the M87 galaxy and the galaxy of our own make probing black hole spacetimes and testing general relativity (GR) possible. The violation of equatorial reflection symmetry of black hole spacetimes is clearly a smoking gun of physics beyond GR. In this paper, we place constraints on the violation of black hole reflection symmetry using the bounds on the ring size of the Sgr A* black hole images, which are consistent with the critical curve radius predicted in GR within $\sim 10\%$. Adopting a theory-agnostic framework, we consider a Kerr-like metric in which the violation of reflection symmetry is parametrized by a single parameter, without altering the multipoles of the black hole. The critical curves are always vertically symmetric due to the existence of hidden symmetry associated with the Killing tensor, even though the spacetime is reflection asymmetric. We find that the size of critical curves is sensitive to the amount of reflection symmetry being violated, and place the first constraints on the parameter space of the model using the Sgr A* images.

15 pages, 3 figures, updated to match the published version

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Cited by in corpus (12)

• Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A${}^{\ast }$
• Constraining a modified gravity theory in strong gravitational lensing and black hole shadow observations
• Testing Rotating Regular Metrics with EHT Results of Sgr A*
• Superradiant evolution of the shadow and photon ring of Sgr A${}^{\star }$
• Probing the Lorentz Symmetry Violation Using the First Image of Sagittarius A*: Constraints on Standard-Model Extension Coefficients
• Deflection angle and shadow of the Reissner-Nordström black hole with higher-order magnetic correction in Einstein-nonlinear-Maxwell fields
• Black Hole Photon Rings Beyond General Relativity
• Motion of particles around a magnetically charged Euler-Heisenberg black hole with scalar hair and the Event Horizon Telescope
• Shadows of Kerr-Vaidya-like black holes
• Self-Gravitating Matter in Stationary and Axisymmetric Black Hole Spacetimes
• Observational features of reflection asymmetric black holes
• Shadow of rotating black holes with consistent thermodynamics