Neutron stars in f (R ,Lm) gravity with realistic equations of state: joint-constrains with GW170817, massive pulsars, and the PSR J0030+0451 mass-radius from NICER data
Abstract
In this work, we investigate neutron stars (NS) in f (R ,Lm) theory of gravity for the case f (R ,Lm) =R +Lm+σ R Lm , where R is the Ricci scalar and Lm the Lagrangian matter density. In the term σ R Lm , σ represents the coupling between the gravitational and particles fields. For the first time the hydrostatic equilibrium equations in the theory are solved considering realistic equations of state and NS masses and radii obtained are subject to joint constrains from massive pulsars, the gravitational wave event GW170817 and from the PSR J0030+0451 mass-radius from NASA's Neutron Star Interior Composition Explorer (NICER) data. We show that in this theory of gravity, the mass-radius results can accommodate massive pulsars, while the general theory of relativity can hardly do it. The theory also can explain the observed NS within the radius region constrained by the GW170817 and PSR J0030+0451 observations for masses around 1.4 M⊙.
- Publication:
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European Physical Journal C
- Pub Date:
- November 2021
- DOI:
- 10.1140/epjc/s10052-021-09785-3
- arXiv:
- arXiv:2106.01841
- Bibcode:
- 2021EPJC...81.1013L
- Keywords:
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- General Relativity and Quantum Cosmology;
- Astrophysics - High Energy Astrophysical Phenomena;
- Nuclear Theory
- E-Print:
- New references added. Matches the published version in EPJC