The equilibrium configurations of neutron stars in the optimized $f(R,T)$ gravity

TL;DR

This paper explores neutron star equilibrium configurations within a specific $f(R,T)$ gravity model, showing slight increases in maximum mass and energy density compared to General Relativity, and indicating potential scale-dependent parameters.

Contribution

It applies a cosmologically derived $f(R,T)$ functional form to neutron stars, demonstrating its viability and revealing possible scale dependence of model parameters.

Findings

Neutron star configurations are achievable in the $f(R,T)$ gravity model.

Maximum mass and energy density are slightly higher than in General Relativity.

Some model parameters differ from cosmological values, indicating scale dependence.

Abstract

We construct equilibrium configurations for neutron stars using a specific $f(R,T)$ functional form, recently derived through gaussian process applied to measurements of the Hubble parameter. By construction, this functional form serves as an alternative explanation for cosmic acceleration, circumventing the cosmological constant problem. Here, we aim to examine its applicability within the stellar regime. In doing so, we seek to contribute to the modified gravity literature by applying the same functional form of a given gravity theory across highly distinct regimes. Our results demonstrate that equilibrium configurations of neutron stars can be obtained within this theory, with the energy density and maximum mass slightly exceeding those predicted by General Relativity. Additionally, we show that the value of some parameters in the $f(R,T)$ functional form must differ from those obtained in cosmological configurations, suggesting a potential scale-dependence for these parameters. We propose that further studies apply this functional form across different regimes to more thoroughly assess this possible dependence.