Influence of minimal gravitational decoupling and pseudo isothermal dark matter halo on mass-radius relation and stability of anisotropic compact stars in f(R,T)–gravity

Abstract

We have provided a new exact solution for anisotropic compact stars to the field equations of $f(R,T)$-gravity via a decoupling technique, with the assumption of a linear $f\left(T\right)$ function and the modified Durgapal-Fuloria metric ansatz. By deforming the radial component of the metric and introducing Pseudo-Isothermal (PI) dark matter (DM) as a new source to the anisotropic seed solution in the process of minimally gravitational decoupling, we have obtained a non-singular solution that meets all physical criteria related to effective density, effective pressure, effective anisotropy, and energy conditions. The present system satisfies the modified Tolman-Oppenheimer-Volkoff equation and achieves stable equilibrium, fulfilling stability criteria such as the adiabatic condition, Herrera cracking concept, and Harrison-Zeldovich-Novikov condition. The influence of minimally gravitational decoupling on the characteristics of the system has been illustrated graphically by varying the decoupling constant (γ). The mass-radius relations are linked to observational constraints and examined for anisotropic stellar systems with and without the effect of minimally gravitational decoupling in both general relativity (GR) and $f(R,T)$-gravity. We found that increasing values of the $f(R,T)$-gravity parameter (χ) and γ reduce the maximum allowable mass of the star. Therefore, increasing the effects of minimally gravitational decoupling and the PI-DM content, subject to the Durgapal-Fuloria metric potential ansatz, cannot support highly compact and supermassive astrophysical objects.