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;