Publications

Abstract

A Schwarzschild black hole is superposed with a family of static axisymmetric thin annular discs whose density is a power law in Weyl radius. The properties of the resulting spacetimes are investigated and compared with those found at inverted Morgan Morgan discs in previous papers. In particular, the course of the total potential, the proper shape of the horizon and the properties of circular motion within the disc (important for physical interpretation of the latter) are illustrated in dependence on 'serial numbers' of the disc (power exponents in its density profile) and on its mass and inner radius. Although the disc densities are regular with all the radial derivatives at the inner rim, the higher derivatives of the potential are still infinite there, giving rise to a curvature singularity. For infinitely thin discs, however, this feature is unavoidable.