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;