Neutron stars in f(R,Lₘ,T) gravity

This study explores the behavior of compact stars within the framework of f(R,Lₘ,T) f ( R , L m , T ) gravity, focusing on the functional form f(R,Lₘ,T) = R + α TLₘ f ( R , L m , T ) = R + α T L m . The modified Tolman–Oppenheimer–Volkoff (TOV) equations are derived and numerically solved for several values of the free parameter α α by considering both quark and hadronic matter—described by realistic equations of state (EoSs). Furthermore, the stellar structure equations are adapted for two different choices of the matter Lagrangian density (namely, Lₘ= p L m = p and Lₘ= -ρ L m = - ρ ), laying the groundwork for our numerical analysis. As expected, we recover the traditional TOV equations in General Relativity (GR) when α → 0 α → 0 . Remarkably, we found that the two choices for Lₘ L m have appreciably different effects on the mass-radius diagrams. Results showcase the impact of α α on compact star properties, while final remarks summarize key findings and discuss implications, including compatibility with observational data from NGC 6397’s neutron star. Overall, this research enhances comprehension of f(R,Lₘ,T) f ( R , L m , T ) gravity’s effects on compact star internal structures, offering insights for future investigations.