Optical Signatures of a Black Hole in Effective Quantum Gravity

Abstract

In this article, we present an investigation of observational signatures of a black hole (BH) in effective quantum gravity (EQG), particularly gravitational weak lensing and shadow analyses with the assumption that the BH is surrounded by uniform and non-uniform plasma. First, we review the spacetime by comparing it with well-known BH spacetimes such as Schwarzschild and Reissner--Nordström BHs. Subsequently, we explore the effect of the uniform and non-uniform plasma on the BH shadow. The results indicate that shadow radii decrease under the influence of the BH charge and both uniform and non-uniform plasma parameters. In addition, we obtain theoretical constraints on the spacetime parameters using observational data from the Event Horizon Telescope (EHT) collaboration. Finally, we study gravitational weak lensing around the BH in EQG surrounded by uniform and non-uniform plasma. It was found that increasing the uniform plasma frequency leads to a rise in the deflection angle and vice versa for the non-uniform plasma.