Area Spectrum of a Rotating Charged Black Hole Solution of Heterotic   String Theory
  The recent proposal of Maggiore that the periodicity of a black hole may be the origin of area quantization law is analyzed in the context of black holes in string theory. We use the period of motion of an outgoing wave, which is shown to be related to the vibrational frequency of the perturbed black hole, to quantize the horizon areas of a Sen black hole. It is shown that the equally spaced area spectrum takes the same form as the obtained by Zeng et. al. for Schwarzschild and Kerr black holes and the spacing is the same as that obtained through the quasinormal mode frequencies. In order to obtain this result, we do not need to use the small angular momentum assumption which is necessary in the quasinormal mode approach. 
Alexis Larranaga
gr-qc hep-th