Shadow of black holes with a plasma environment in 4D Einstein-Gauss-Bonnet gravity

TL;DR

This paper investigates how the shadow of rotating black holes is affected by plasma environments within the 4D Einstein-Gauss-Bonnet gravity framework, providing new insights into observational signatures.

Contribution

It introduces a model for black hole shadows in plasma environments in 4D Einstein-Gauss-Bonnet gravity, including new observables for shadow characterization.

Findings

Derived the shadow contours for plasma-embedded rotating black holes.

Proposed three observables to quantify shadow position, size, and shape.

Analyzed the influence of plasma on black hole shadow features.

Abstract

We study the shadow cast by rotating black holes surrounded by plasma in the context of the 4D Einstein-Gauss-Bonnet theory of gravity. The metric for these black holes results from applying the Newman-Janis algorithm to a spherically symmetric solution. We obtain the contour of the shadow for a plasma frequency model that allows a separable Hamilton-Jacobi equation. We introduce three observables in order to characterize the position, size, and shape of the shadow.