Energy and Angular Momentum of Dilaton Black Holes
  Following a prior paper, we review the results for the energy and angular momentum of a Kerr-Newman black hole, and then calculate the same properties for the case of a generalised rotating dilaton of the type derived, without rotation, by Garfinkle, Horowitz, and Strominger (1991; 1992). We show that there is, as far as it refers only to the energy and angular momentum, an interaction among the fields, so that, the gravitational and electromagnetic fields may be obscured by the strength of the scalar field. 
Marcelo Samuel Berman