Year: 2026
Type: article
Abstract: This study investigates the impact of the Rastall coupling parameter on the internal structure, global properties, and stability of compact stellar configurations. Within the framework of Rastall gravity, an anisotropic relativistic stellar model is developed to explore how deviations from general relativity (GR) modify the fundamental physical properties of ultra-dense matter. A systematic comparison with the corresponding GR configuration is performed to elucidate the effects of the Rastall parameter on the density and pressure profiles, compactness, and other physical quantities. The resulting mass–radius (M–R) and moment of inertia–mass (I–M) relations demonstrate that Rastall corrections can significantly enhance the maximum mass and moment of inertia supported by compact stars, compared with the corresponding GR counterpart. Furthermore, the predicted M–R and M-I relations are confronted with astrophysical observational constraints associated with the neutron-star candidates, including PSR J0437-4715, PSR J222-0137, PSR J1614-2230, PSR J0348+0432. These comparisons provide bounds on the maximum permissible mass of the configurations and demonstrate their compatibility with the astrophysical observations. The physical viability and stability of the model are further examined through the standard energy conditions, causality constraints, adiabatic-index criterion, and hydrostatic equilibrium described by the generalized Tolman–Oppenheimer–Volkoff equation. Overall, our results reveal that the Rastall coupling parameter plays a significant role in determining the structural and stability properties of compact stars, highlighting modified Rastall gravity as a viable geometric extension of GR for modeling ultra-dense astrophysical systems.
Source: Scientific Reports
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,690
OpenAlex ID: W7221030938