Publication date: Jan 2011
Abstract:
Influence of cosmological constant on toroidal fluid configurations
around charged spherically symmetric black holes and naked singularities
is demostrated by study of perfect-fluid tori with uniform distribution
of specific angular momentum orbiting in the
Reissner-Nordström-(anti-)de Sitter spacetimes. Toroidal
configurations are allowed only in the spacetimes admitting existence of
stable circular geodesics. Configurations with marginally closed
equipotential (equipressure) surfaces crossing itself in a cusp allow
accretion (through the inner cusp) and/or excretion (through the outer
cusp) of matter from the toroidal configuration. Detailed classification
of the Reissner-Nordström-(anti-)de Sitter spacetimes according to
properties of the marginally stable tori is given. It is demonstrated
that in the Reissner-Nordström-de Sitter naked-singularity
spacetimes an interesting phenomenon of doubled tori can exist enabling
exchange of matter between two tori in both inward and outward
directions. In naked-singularity spacetimes the accretion onto the
central singularity is impossible due to existence of a potential
barrier.
Authors:
Kucáková, Hana; Slaný, Petr; Stuchlík, Zdenĕk;