**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;