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;