Physical effects in the Vaidya–Einstein–Kerr spacetime

We investigate some physical effects in the Vaidya–Einstein–Kerr (VEK) spacetime which represents the spacetime of the Kerr black-hole in the background of the non-flat Einstein universe. We have chosen for our study the nature of circular geodesics and the phenomenon of gyroscopic precession in the VEK spacetime. We show that the nature of the circular geodesics is radically altered by the presence of the background. Turning to gyroscopic precession we show that a novel feature emerges in that the background affects the precession in two different ways, one by coupling to rotation and another in a direct manner. We investigate also several special cases of general precession.