Universal scaling form of AC response in variable range hopping
  We have studied the AC response of a hopping model in the variable range hopping regime by dynamical Monte Carlo simulations. We find that the conductivity as function of frequency follows a universal scaling law. We also compare the numerical results to various theoretical predictions. Finally, we study the form of the conducting network as function of frequency. 
Joakim Bergli and Yuri M. Galperin
cond-mat.dis-nn