Minimally Deformed Regular Bardeen Black Hole Solutions in Rastall Theory

TL;DR

This paper extends the regular Bardeen black hole solutions within Rastall theory using minimal geometric deformation, analyzing their physical and thermodynamic properties, and revealing violations of asymptotic flatness and energy conditions.

Contribution

It introduces new black hole solutions in Rastall theory via minimal geometric deformation and explores their physical and thermodynamic characteristics.

Findings

Both models violate asymptotic flatness.

Energy conditions are violated, indicating exotic matter.

Models show thermodynamic stability despite violations.

Abstract

In this study, we utilize the minimal geometric deformation technique of gravitational decoupling to extend the regular Bardeen black hole, leading to the derivation of new black hole solutions within the framework of Rastall theory. By decoupling the field equations associated with an extended matter source into two subsystems, we address the first subsystem using the metric components of the regular Bardeen black hole. The second subsystem, incorporating the effects of the additional source, is solved through a constraint imposed by a linear equation of state. By linearly combining the solutions of these subsystems, we obtain two extended models. We then explore the distinct physical properties of these models for specific values of the Rastall and decoupling parameters. Our investigations encompass effective thermodynamic variables such as density and anisotropic pressure, asymptotic flatness, energy conditions, and thermodynamic properties including Hawking temperature, entropy, and specific heat. The results reveal that both models violate asymptotic flatness of the resulting spacetimes. The violation of energy conditions indicate the presence of exotic matter, for both models. Nonetheless, the energy density, radial pressure, as well as the Hawking temperature exhibit acceptable behavior, while the specific heat and Hessian matrix suggest thermodynamic stability.