Neutron Stars in the Context of f(T,T) Gravity

Abstract

In this work, we investigate the existence of neutron stars (NS) in the framework of f(T,T) gravity, where T is the torsion tensor and T is the trace of the energy–momentum tensor. The hydrostatic equilibrium equations are obtained, however, with p and ρ quantities passed on by effective quantities p¯ and ρ¯, whose mass–radius diagrams are obtained using modern equations of state (EoS) of nuclear matter derived from relativistic mean field models and compared with the ones computed by the Tolman–Oppenheimer–Volkoff (TOV) equations. Substantial changes in the mass–radius profiles of NS are obtained even for small changes in the free parameter of this modified theory. The results indicate that the use of f(T,T) gravity in the study of NS provides good results for the masses and radii of some important astrophysical objects, as, for example, the NS of low-mass X-ray binary in NGC 6397, the millisecond pulsar PSR J0740+6620 and the GW170817 event. In addition, radii results inferred from the Lead Radius Experiment (PREX-2) can also be described for certain parameter values.