Publication date: Dec 2004
Abstract:
We consider basic properties of both the geometrically thin and thick accretion disks in the Kerr-de Sitter black-hole and naked-singularity spacetimes. The properties are determined by character of the equatorial circular geodesics of these spacetimes and by the equilibrium configurations of a perfect fluid rotating around their symmetry axis. Transformation of a Kerr-de Sitter naked singularity into an extreme black hole due to accretion in the thin disks is briefly discussed for both the plus-family and minus-family disks. It is shown that such a conversion leads to an abrupt instability of the innermost parts of the plus-family accretion disks that can have strong observational consequences.
Authors:
Stuchlík, Zdeněk; Slaný, Petr;