Spinning black holes in astrophysical environments

TL;DR

This paper introduces new stationary, axially-symmetric black hole solutions influenced by anisotropic fluids, analyzing their physical properties, shadows, and deviations from Kerr metrics, especially at high spins.

Contribution

It provides novel solutions for rotating black holes in astrophysical environments, extending the Kerr metric with anisotropic matter effects.

Findings

Deviations from Kerr increase with black hole spin.

Black hole shadows and image features are affected by the surrounding anisotropic fluid.

Energy conditions are analyzed for these new solutions.

Abstract

We present stationary and axially-symmetric black hole solutions to the Einstein field equations sourced by an anisotropic fluid, describing rotating black holes embedded in astrophysical environments. We compute their physical properties, including quantities associated with the circular geodesics of massless and massive particles, analyze their shadows and image features, and energy conditions. Overall, we find that deviations from the Kerr metric grow with spin.