Dynamic interplay of anisotropy and matter–geometry coupling in stellar structures: A comprehensive study on the stability of pulsars 4U 1820-30 and LMC X-4

Abstract

This study investigates the behavior of dense celestial objects within the context of $f(R,L_m,T)$ theory. We develop modified Einstein field equations that account for the anisotropic configured static interior spacetime. By applying two specific constraints associated with the radial metric function and anisotropic pressure, we find a couple of solutions to these highly non-linear gravitational equations. For both models, we encounter differential equations whose integration yield constants which are determined through matching conditions. Additionally, the requirement of vanishing radial pressure at the hypersurface also plays an important role in this context. Furthermore, we graphically evaluate certain conditions whose fulfillment ensures the model’s feasibility under different parametric values. For this, we take into account the observational data of two compact stars 4U 1820-30 and LMC X-4. We conclude both our models to be well-aligned with the required viability and stability criteria. We must highlight here that our study advances the understanding of how $f(R,L_m,T)$ gravity affects the internal structure of compact stars, providing valuable insights for future explorations.