Physical effects in the Vaidya–Einstein–Kerr spacetime

Abstract

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.

The Carter constant and Petrov classification of the Vaidya–Einstein–Kerr spacetime

“…In a series of studies [7][8][9][10] we have been investigating non-vacuum black holes in non-flat backgrounds in order to compare and contrast the nature and features of such black holes with their usual counterparts. Focusing on the Vaidya-Einstein-Schwarzschild (VES) and the Vaidya-Einstein-Kerr (VEK) black holes which essentially represent nonvacuum black holes in the background of the Einstein universe [11], we have showed [8][9][10] that much insight may be gained by studying the non-flat versions of the classical tests, the nature of circular geodesics as well as physical effects such as gyroscopic precession. In the present paper we investigate in detail the existence of the Carter constant and the Petrov classification of the above non-vacuum, non-flat spacetimes.…”