Publication date: Dec 2014
Abstract:
We study the non-monotonic Keplerian velocity profiles related to
locally nonrotating 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 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 = 0.41005 (and spin larger than a =
0.76808). 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, Z.; Blaschke, M.; Slaný, P.;