Mass angular momentum and charge inequalities for black holes in   Einstein-Maxwell-axion-dilaton gravity
  Mass angular momentum and charge inequalities for axisymmetric maximal time-symmetric initial data invariant under an action of U(1) group, in Einstein-Maxwell-axion-dilaton gravity being the low-energy limit of the heterotic string theory, is established. We assume that data set with two asymptotically flat regions is given on smooth simply connected manifold. We also pay attention to the area momentum charge inequalities for a closed orintabler two-dimensional spacelike surface embedded in the spacetime of the considered theory. 
Marek Rogatko
hep-th gr-qc