Wave Properties of Plasma Surrounding the Event Horizon of a Non-Rotating Black Hole

TL;DR

This study investigates wave behaviors of cold, isothermal plasma near a Schwarzschild black hole's event horizon, revealing that no information escapes and pressure affects wave dispersion.

Contribution

It provides a detailed analysis of plasma wave properties near a non-rotating black hole using Fourier analysis of GRMHD equations, including dispersion relations and refractive index.

Findings

No information can be obtained from the Schwarzschild magnetosphere.

Pressure inhibits normal wave dispersion.

Dispersive properties vary with plasma conditions near the horizon.

Abstract

We have studied the wave properties of the cold and isothermal plasma in the vicinity of the Schwarzschild black hole event horizon. The Fourier analyzed perturbed 3+1 GRMHD equations are taken on the basis of which the complex dispersion relations are obtained for non-rotating, rotating non-magnetized and rotating magnetized backgrounds. The propagation and attenuation vectors along with the refractive index are obtained (shown in graphs) to study the dispersive properties of the medium near the event horizon. The results show that no information can be obtained from the Schwarzschild magnetosphere. Further, the pressure ceases the existence of normal dispersion of waves.