Quantum effects on the black hole shadow and deflection angle in presence of plasma

TL;DR

This study examines how quantum effects and plasma media influence the optical properties of Schwarzschild black holes, including shadow size and light deflection, highlighting the minimal detectability of quantum effects with current technology.

Contribution

It introduces the impact of plasma media on black hole shadows and light deflection, incorporating quantum effects into the analysis of RGI Schwarzschild black holes.

Findings

Quantum effects slightly alter the black hole geometry.

Plasma media significantly modify light trajectories and shadow images.

Quantum effects are practically undetectable with current observational technology.

Abstract

In this paper, optical properties of renormalization group improved (RGI) Schwarzschild black hole (BH) are investigated in plasma medium. Starting from the equations of motions in plasma medium, we have shown how the shadow radius of the RGI black hole is modified. To this end, we have computed the deflection angle of light in the weak gravity regime for uniform and non-uniform plasma medium. Importantly, due to the plasma medium, we find that the equations of motions for light obtained from the radiating and infalling/rest gas has to be modified. This in turn, changes and modifies the expression for the intensity observed far away from the black hole. Finally, we have obtained the shadow images for the RGI black hole for different plasma models. Even thought, quantum effect changes the background geometry, these effects are very small and, practically, it is impossible to detect them with the present technology using the supermassive black hole shadows. The parameter $\Omega$ encodes the quantum effects and, in principle, one expects such quantum effects to play a significant role only for very small black holes. On the other hand, the effect of plasma medium can play important role on the optical appearance of black holes since they effect and modify the equations of motions.