Investigation of the rotation effects on high--density matter in hybrid stars

Abstract

The equation of state (EOS) of high-density matter is still not clear and several recent observations indicate restrictions to EOSs. Theoretical studies should thus elucidate EOSs at high density and/or high temperature. Many theoretical studies have attempted to account for the effect of rotation of rapidly rotating neutron stars (pulsars), which are commonly observed astronomical objects having high-density interiors. Furthermore, neutron stars generate a strong magnetic field. Several recent studies indicate that this magnetic field exerts some restrictions on the EOS. Theoretical studies should thus incorporate these effects. In this paper, we focus on the effect of rotation. We find that one of our EOSs is consistent with these observations, and another is inconsistent. We also find an important relation between radius and rotation.