Massive Compact Bardeen Stars with Conformal Motion

TL;DR

This paper explores solutions to Einstein-Maxwell equations for compact stars using the Bardeen model as exterior spacetime, demonstrating that Bardeen geometry allows for more massive charged stellar objects consistent with observed pulsars.

Contribution

It introduces a novel analysis of Bardeen spacetime as an exterior for charged stars, showing it supports more massive configurations than Reissner-Nordstrom models.

Findings

Bardeen model yields more massive stellar objects.

Energy conditions are satisfied in the model.

Masses obey Andreasson's limit for charged stars.

Abstract

The main focus of this paper is to discuss the solutions of Einstein-Maxwell's field equations for compact stars study. We have chosen the MIT bag model equation of state for the pressure-energy density relationship and conformal Killing vectors are used to investigate the appropriate forms for metric coefficients. We impose the boundary conditions, by choosing the Bardeen model to describe as an exterior spacetime. The Bardeen model may provide the analysis with some interesting results. For example, the extra terms involved in the asymptotic representations as compared to the usual Reissner-Nordstrom case may influence the mass of a stellar structure. Both energy density and pressure profiles behave realistically except a central singularity. It is shown that the energy conditions are satisfied in our study. The equilibrium conditions through TOV equation and stability criteria through Adiabatic index for the charged stellar structure study are investigated. Lastly, we have also provided a little review of the case with Reissner-Nordstrom spacetime as an exterior geometry for the matching condition. In both cases, the masses obey the Andreasson's limit $\sqrt{M} \leq \sqrt{R}/3+\sqrt{R/9+q^2/3R}$ requirement for a charged star. Conclusively, the results show that Bardeen model geometry provides more massive stellar objects as compared to usual Reissner-Nordstrom spacetime. In particular, the current study supports the existence of realistic massive structures like PSR J $1614-2230$.