Extending Finch-Skea Isotropic Model to Anisotropic Domain in Modified $f(\mathcal{R},\mathcal{T})$ Gravity

TL;DR

This paper extends the Finch-Skea isotropic stellar model to anisotropic configurations within $f(R,T)$ gravity using gravitational decoupling, deriving new solutions and analyzing their physical viability for stellar objects.

Contribution

It introduces a novel application of gravitational decoupling to generate anisotropic solutions in $f(R,T)$ gravity from the Finch-Skea model, expanding the modeling of compact stars.

Findings

First two models are physically viable for all parameters.

Graphical analysis supports the models' relevance to stellar objects.

Derived solutions match observed star parameters like LMC X-4.

Abstract

This paper considers the Finch-Skea isotropic solution and extends its domain to three different anisotropic interiors by using the gravitational decoupling strategy in the context of $f(\mathcal{R},\mathcal{T})$ gravitational theory. For this, we consider that a static spherical spacetime is initially coupled with the perfect matter distribution. We then introduce a Lagrangian corresponding to a new gravitating source by keeping in mind that this new source produces the effect of pressure anisotropy in the parent fluid source. After calculating the field equations for the total matter setup, we apply a transformation on the radial component, ultimately providing two different systems of equations. These two sets are solved independently through different constraints that lead to some new solutions. Further, we consider an exterior spacetime to calculate three constants engaged in the seed Finch-Skea solution at the spherical interface. The estimated radius and mass of a star candidate LMC X-4 are utilized to perform the graphical analysis of the developed models. It is concluded that only the first two resulting models are physically relevant in this modified theory for all the considered parametric choices.