Contribution of the cosmological constant to the bending of light in Kerr–de Sitter spacetime

Abstract

We examine the effect of the cosmological constant $\ensuremath{\Lambda}$ on the angle of deflection of null geodesics in the equatorial plane of the Kerr--de Sitter spacetime. This is done by employing a procedure used recently by Rindler and Ishak to obtain the bending angle of light in the Schwarzschild--de Sitter geometry. We show that this approach yields a contribution from the cosmological constant in the expression for the bending angle.