Scattering of scalar waves by rotating black holes (Q2729254)

The scattering of a massless scalar field by a rotating (Kerr) black hole is studied. Special attention is made on the waves traveling in a direction not identical to the axis of rotation of the black hole. The analysis is based on the phase shifts of the partial spherical waves. These are calculated numerically. The result is compared with the corresponding results of scattering off a spherically-symmetric (Schwarzschild) Black hole and those of scattering a wave incident axially to a rotating black hole. The diffraction pattern is explained in terms of the frame-dragging effect of a rotating black hole.