ABSTRACT
Relativity the curvature in the geometry of four-dimensional spacetime, which manifests itself as gravitation, is the result of mass. In the case of a compact stellar configuration, it is the star’s mass that acts as the source which curves the geometry of spacetime inside and outside of the star. If the star is rotating, then the so-called Lense-Thirring or frame dragging effect comes into play induced by the mass of the rotating star, in the direction of the star’s rotation. The calculation of effects became possible when Albert Einstein formulated his general theory of relativity in 1916, and was carried out in 1918 by Walter Thirring. Using the weak-field approximation to Einstein’s equations, he found that a slowly rotating mass shell drags along the inertial frames within it. The chapter describes the construction of models of neutron and strange matter stars, the general theory of relativity, which culminates in Einstein’s field equations.
