Filling the Shadow: A Propositional Model of Gravastar Accretion in f ( R , L m , T ) Gravity

While General Relativity remains our most rigorously tested framework for gravitation, the theoretical persistence of singularities within standard black hole solutions continues to motivate the exploration of mathematically regular alternatives. Gravitational vacuum stars (gravastars) offer a non-singular model, substituting the event horizon with a physical, ultra-stiff thin shell. Recent studies have demonstrated that extended theories, such as [Formula: see text] gravity, can structurally support these objects by utilizing the non-minimal coupling between geometry and matter. Building upon these static foundations, this paper presents a propositional model to explore the dynamic interactions between modified-gravity gravastars and equatorial accretion flows. By numerically solving the modified Tolman-Oppenheimer-Volkoff equations and defining a physical thin-shell boundary, we construct a mathematically regular rotating metric ansatz using the Azreg-Aïnou algorithm. We demonstrate through a parameter sensitivity analysis that the modified gravity coupling parameter systematically alters the effective potential, shifting the location of the Innermost Stable Circular Orbit (ISCO). Furthermore, we explore the idealized thermodynamics of plasma colliding with the gravastar surface using a two-component thermal emission model, suggesting a distinct high-temperature signature that could theoretically produce a “filled-in” central shadow in interferometric observations. While acknowledging the challenges of observational degeneracy and the deliberate omission of complex radiation pressure feedback, we offer these geometric and thermal signatures as a transparent conceptual baseline to motivate future general relativistic magnetohydrodynamic (GRMHD) campaigns.