Structure and stability of rotating relativistic neutron stars

Abstract

The influence of rotation on the bulk properties of rotating neutron stars is examined, and the general-relativistic limit on the rotational frequency set by the growth of instabilities driven by gravitational radiation reaction (which are moderated by the presence of viscosity) is calculated. The analysis is applied to four different realistic neutron-matter equations of state derived in the framework of the relativistic Green-function method. Self-consistent calculations for the construction of rotating neutron-star models of gravitational masses 1.5 and 1.9 solar mass are performed. Hartle's formalism leads to results for the bulk properties of the rotating models that are of comparable size with those obtained by a direct numerical solution of Einstein's field equations. It is established that dynamical two-particle correlations influence the neutron-matter equation of state, which does not exceed densities that are close to the density of normal nuclear matter, and also have an impact on the properties of lighter neutron stars and the properties of a star rotating at its Keplerian angular velocity.