Supercharge and background perturbations of multi-black hole systems

We consider spin-3/2 fields on backgrounds of several extreme black holes. The existance of killing spinors on these backgrounds allows one to assign, although not uniquely, supercharge parameters associated with the Rarita-Schwinger field to the individual black holes. For regular static spin-3/2 fields the values of these supercharges are strongly constrained by the background configuration. Furthermore, we establish an integral relation between Rarita-Schwinger fields and first order perturbations of the background: The supercharge can be connected to the first order changes of the masses and the electric charges. Special configuration that admit only zero total supercharge are given. (Author)