**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;