Publication date: Sep 2011
Abstract:
We study the non-monotonic Keplerian velocity profiles related to
locally non-rotating frames (LNRF) in the field of near-extreme
braneworld Kerr black holes and naked singularities in which the
non-local gravitational effects of the bulk are represented by a
braneworld tidal charge b and the 4D geometry of the spacetime structure
is governed by the Kerr-Newman geometry. We show that positive tidal
charge has a tendency to restrict the values of the black hole
dimensionless spin a admitting the existence of the non-monotonic
Keplerian LNRF-velocity profiles; the non-monotonic profiles exist in
the black hole spacetimes with tidal charge smaller than b = 0.410 05
(and spin larger than a = 0.768 08). With decreasing value of the tidal
charge (which need not be only positive), both the region of spin
allowing the non-monotonicity in the LNRF-velocity profile around
braneworld Kerr black hole and the velocity difference in the
minimum-maximum parts of the velocity profile increase implying growing
astrophysical relevance of this phenomenon.
Authors:
Stuchlík, Zdeněk; Blaschke, Martin; Slaný, Petr;