Publication date: May 1991
Abstract:
We study the radial motion along null geodesics in the Reissner-
Nordström-de Sitter and Kerr-de Sitter space-times. We analyze the
properties of the effective potential and we discuss circular orbits. We
find that: 1) the radius of circular photon orbits in the Reissner-
Nordström-de Sitter space-times does not depend on the cosmological
constant. We show also how this is related to properties of the optical
reference geometry. 2) For a specific range of the cosmological
constant, photons with high impact parameter may travel radially between
the cosmological horizon and the black hole horizon in the equatorial
plane of the Kerr-de Sitter space-times.
Authors:
Stuchlik, Zdenek; Calvani, Massimo;