GREYBODY FACTORS FOR ROTATING BLACK-HOLES IN 4 DIMENSIONS

We present the wave equation for a minimally coupled scalar field in t he background of a rotating four-dimensional black hole that is parame trized by its mass, angular momentum, and four independent U(1) charge s, The near horizon structure is identical to the five-dimensional cas e, and suggestive of an underlying description in string theory that i s valid in the general non-extremal case. We calculate the greybody fa ctors for the Hawking radiation. For sufficiently large partial wave n umber the emission spectrum can be calculated for general non-extremal black holes and any particle energy. We interpret this spectrum in te rms of a multi-body process in an effective string theory. (C) 1997 El sevier Science B.V.