Relativistic model for anisotropic strange stars

TL;DR

This paper develops a singularity-free, anisotropic model for strange stars using Einstein's field equations, the Schwarzschild exterior metric, and the MIT bag model, analyzing their physical properties and stability.

Contribution

It presents a novel anisotropic strange star model that satisfies physical conditions, energy criteria, and stability tests within general relativity, incorporating the MIT bag model for quark matter.

Findings

Anisotropy increases with radius and peaks at the surface.

Model satisfies energy conditions and stability criteria.

Maximum mass and radius are calculated for different bag constants.

Abstract

In this article, we attempt to find a singularity free solution of Einstein's field equations for compact stellar objects, precisely strange (quark) stars, considering Schwarzschild metric as the exterior spacetime. To this end, we consider that the stellar object is spherically symmetric, static and anisotropic in nature and follows the density profile given by Mak and Harko (2002), which satisfies all the physical conditions. To investigate different properties of the ultra-dense strange stars we have employed the MIT bag model for the quark matter. Our investigation displays an interesting feature that the anisotropy of compact stars increases with the radial coordinate and attains its maximum value at the surface which seems an inherent property for the singularity free anisotropic compact stellar objects. In this connection we also perform several tests for physical features of the proposed model and show that these are reasonably acceptable within certain range. Further, we find that the model is consistent with the energy conditions and the compact stellar structure is stable with the validity of the TOV equation and Herrera cracking concept. For the masses bellow the maximum mass point in mass vs radius curve the typical behavior achieved within the framework of general relativity. We have calculated the maximum mass and radius of the strange stars for the three finite values of bag constant $B_g$.