The Surface Gravitational Redshift of a Proto Neutron Star

The influence of the σ* and Φ mesons on the surface gravitational redshift of a proto neutron star is investigated within the framework of relativistic mean field theory for the baryon octet n,p,Λ,Σ^-,Σ⁰, Σ⁺,Ξ^-,Ξ⁰ system. It is found that, compared with those without considering the contribution of σ^* and Φ mesons, the surface gravitational redshift decreases, corresponding to the maximum value of the mass decreasing from 0.2220 to 0.1937, about 12.7%. It is also found that the appearance of σ^* and Φ mesons makes the surface gravitational redshift as a function of M/R decrease too, with M and R being the mass and radius of the proto neutron star.