Bardeen black hole surrounded by perfect fluid dark matter

TL;DR

This paper derives an exact solution for a Bardeen black hole surrounded by perfect fluid dark matter, analyzes its thermodynamics, stability, and rotation, and explores energy extraction processes.

Contribution

It introduces a new exact solution incorporating dark matter effects into Bardeen black holes and studies their thermodynamic and rotational properties.

Findings

Existence of a critical radius where heat capacity diverges

Thermodynamic stability depends on black hole parameters

Rotation affects horizon and ergosphere structure

Abstract

We derive an exact solution of the spherically symmetric Bardeen black hole surrounded by perfect fluid dark matter (PFDM). By treating the magnetic charge $g$ and dark matter parameter $\alpha$ as thermodynamic variables, we find that the thermodynamic first law and the corresponding Smarr formula are satisfied. The thermodynamic stability of the black hole is also studied. The result show that, there exists a critical radius $r_{+}^{C}$, where the heat capacity diverges, suggesting that the black hole is thermodynamically stable in the range $0<r_{+}<r_{+}^{C}$. In addition, the critical radius $r_{+}^{C}$ increases with the magnetic charge $g$ and decreases with the dark matter parameter $\alpha$. Applying the Newman-Janis algorithm, we generalize the spherically symmetric solution to the corresponding rotating black hole. With the metric at hand, the horizons and ergospheres are studied. It turns out that for a fixed dark matter parameter $\alpha$, in a certain range, with the increase of the rotation parameter $a$ and magnetic charge $g$, the Cauchy horizon radius increases while the event horizon radius decreases. Finally, we investigate the energy extraction by the Penrose process in rotating Bardeen black hole surrounded by PFDM.