Properties of neutron star are investigated by an available relativistic ab initio method , i.e. , the relativistic Brueckner-Hartree-Fock ( RBHF ) model , with the latest high-precision relativistic charge-dependent potentials , pvCD-Bonn A , B , C. The neutron star matter is solved within the beta equilibrium and charge neutrality conditions in the framework of RBHF model .
Comparing to the conventional treatment , where the chemical potential of lepton was approximately represented by the symmetry energy of nuclear matter , the equation of state ( EOS ) of neutron star matter in the present self-consistent calculation with pvCD-Bonn B has striking difference above the baryon number density n _ { b } = 0.55 fm ^ { -3 } .
However , these differences influence the global properties of neutron star only about 1 \% \sim 2 \% .
Then , three two-body potentials pvCD-Bonn A , B , C , with different tensor components , are systematically applied in RBHF model to calculate the properties of neutron star .
It is found that the maximum masses of neutron star are around 2.21 \sim 2.30 M _ { \odot } and the corresponding radii are R = 11.18 \sim 11.72 km .
The radii of 1.4 M _ { \odot } neutron star are predicated as R _ { 1.4 } = 12.34 \sim 12.91 km and their dimensionless tidal deformabilities are \Lambda _ { 1.4 } = 485 \sim 626 .
Furthermore , the direct URCA process in neutron star cooling will happen from n _ { b } = 0.414 \sim 0.530 fm ^ { -3 } with the proton fractions , Y _ { p } = 0.136 \sim 0.138 .
All of the results obtained from RBHF model only with two-body pvCD-Bonn potentials completely satisfy various constraints from recent astronomical observations of massive neutron stars , gravitational wave detection ( GW 170817 ) , and mass-radius simultaneous measurement ( NICER ) .