Charged anisotropic fluid sphere in comparison with its uncharged analogue through extended geometric deformation

In this article, we consider a known charged isotropic Durgapal IV solution and extend it to its anisotropic version using gravitational decoupling by means of extended geometric deformation (EGD) approach, which provides a more generic way for the decoupling of gravitational sources. Following this approach, we employ linear transformation on both metric potentials and split the original set of field equations into two subsystems. The first subsystem corresponds to charged isotropic fluid while the second one is related to the additional source, crucial for anisotropy. The isotropic one is specified through metric functions of known charged isotropic solution, while the solution of second sector is determined by considering two different constraints on additional source theta(b)(a), i.e., mimicking of isotropic pressure and a linear equation of state which relating theta(0)(0) and theta(1)(1). The matching conditions at the stellar surface are discussed in detail, where outer geometry is represented by Reissner-Nordstrom solution. We discuss the physical properties of the stellar model in comparison with its uncharged anisotropic analogue, which is provided in Appendix. Physical analysis is carried out using different physical indicators including energy conditions, equilibrium equation, casualty condition, Herrera's cracking concept, adiabatic index, compactness and surface redshift for compact star PSR J 1416-2230. We find that anisotropic stellar model is stable for larger range of gamma (coupling constant) in the presence of electric charge and the effects of anisotropy are diminished near stellar surface.

Automated summary

In this article, a known charged isotropic Durgapal IV solution is extended to its anisotropic version using the extended geometric deformation (EGD) approach. The physical properties of the anisotropic stellar model are studied and compared with its uncharged anisotropic analogue. The results show that the anisotropic stellar model is stable for a larger range of the coupling constant in the presence of electric charge, and the effects of anisotropy are diminished near the stellar surface.