Publication date: Oct 2016
Abstract:
We show that the braneworld rotating Kerr-Newman black hole and naked
singularity spacetimes with both positive and negative braneworld tidal
charge parameters can be separated into 14 classes according to the
properties of circular geodesics governing the Keplerian accretion. We
determine the efficiency of the Keplerian accretion disks for all
braneworld Kerr-Newman spacetimes. We demonstrate the occurrence of an
infinitely deep gravitational potential in Kerr-Newman naked singularity
spacetimes having the braneworld dimensionless tidal charge b ∈(1 /4 ,1
) and the dimensionless spin a ∈(2 √{b }-√{b (4 b -1 ) } , 2 √{b }+√{b
(4 b -1 ) }) , implying unbound efficiency of the Keplerian accretion
and the possibility of extracting the whole naked singularity mass.
Therefore, we call them braneworld „mining-unstable“ Kerr-Newman naked
singularity spacetimes. Fundamental restriction on the relevance of the
extraordinary—but fully classical—phenomenon of the mining instability
is given by validity of the assumption of geodesic motion of the
accreting matter.
Authors:
Blaschke, Martin; Stuchlík, Zdeněk;