Complexity-controlled modeling of charged 4U 1820–30 in the Starobinsky framework of modified gravity

Abstract

In this study, we investigate nonlinear, radiating, charged, and anisotropic stellar configurations in the framework of f(R) gravity, adopting the Starobinsky model as a representative curvature-corrected modification of general relativity. The stellar models are developed by employing two formulations of the generalized polytropic equation of state: one expressed in terms of mass density and the other in terms of energy density. This dual formulation provides a broader phenomenological description of dense-matter behavior in compact stellar interiors. The gravitational complexity factor is incorporated as an additional constraint to regulate the effects of density inhomogeneity, pressure anisotropy, charge, and radiation density, thereby supporting the construction of mathematically consistent and physically acceptable configurations. To examine the viability of the resulting models, we perform a detailed graphical analysis of the relevant physical variables for the compact object \(4U~1820-30\). The obtained profiles satisfy the imposed regularity, stability, causality, and energy-condition requirements for the selected parameter ranges. These results indicate that complexity-controlled polytropic models in modified gravity may provide a useful framework for describing dense, charged, anisotropic compact objects.