Duality Near Quantum Hall Transitions
  A recent experiment by Shahar et al, on the phase transitions between quantum Hall states and the insulator, found that the current-voltage characteristics in the two phases are related by symmetry. It was suggested in this work that this is evidence for charge-flux duality near quantum Hall transitions. Here we provide details of this analysis. (Appearances notwithstanding, this is a theoretical paper.) 
E. Shimshoni (Oranim-Haifa), S. L. Sondhi (Princeton) and D. Shahar   (Princeton)