摘要
Considering the octet baryons in relativistic mean field theory and selecting entropy per baryon S=1, we calculate and discuss the influence of U bosons on the equation of state, mass-radius, moment of inertia and gravitational redshift of massive protoneutron stars （PNSs）. The effective coupling constant gu of U bosons and nucleons is selected from 0 to 70 GeV-2. The results indicate that U bosons will stiffen the equation of state （EOS）. The influence of U bosons on the pressure is more obvious at low density than high density, while the influence of U bosons on the energy density is more obvious at high density than low density. The U bosons play a significant role in increasing the maximum mass and radius of PNS. When the value of gu changes from 0 to 70 GeV-2, the maximum mass of a massive PNS increases from 2.11M to 2.58Me, and the radius of a PNS corresponding to PSR J0348＋0432 increases from 13.71 km to 24.35 km. The U bosons will increase the moment of inertia and decrease the gravitational redshift of a PNS. For the PNS of the massive PSR J0348＋0432, the radius and moment of inertia vary directly with gu, and the gravitational redshift varies approximately inversely with gu.
Considering the octet baryons in relativistic mean field theory and selecting entropy per baryon S=1, we calculate and discuss the influence of U bosons on the equation of state, mass-radius, moment of inertia and gravitational redshift of massive protoneutron stars （PNSs）. The effective coupling constant gu of U bosons and nucleons is selected from 0 to 70 GeV-2. The results indicate that U bosons will stiffen the equation of state （EOS）. The influence of U bosons on the pressure is more obvious at low density than high density, while the influence of U bosons on the energy density is more obvious at high density than low density. The U bosons play a significant role in increasing the maximum mass and radius of PNS. When the value of gu changes from 0 to 70 GeV-2, the maximum mass of a massive PNS increases from 2.11M to 2.58Me, and the radius of a PNS corresponding to PSR J0348＋0432 increases from 13.71 km to 24.35 km. The U bosons will increase the moment of inertia and decrease the gravitational redshift of a PNS. For the PNS of the massive PSR J0348＋0432, the radius and moment of inertia vary directly with gu, and the gravitational redshift varies approximately inversely with gu.
基金
Supported by National Natural Science Foundation of China(11175147)
