Electron-electron interactions and quenched randomness play a crucial role in determining universal properties of quantum Hall (QH) transitions; yet many of their combined effects remain poorly understood. By formulating the problem in a dual composite fermion representation, we arrive at the following conclusions. With 1/r interactions, the transitions are superuniversal (i.e. both fractional and integer QH transitions belong to the same universality class). In this case, there are two dynamical scaling regimes, one with scaling exponent z=1, and another with z=2. Up to leading corrections to scaling, all other exponents are governed by the non-interacting network model. We conjecture that with short-ranged interactions, the transitions are not superuniversal, and that there is a single dynamical scaling exponent, z=2. We substantiate our conclusions by analyzing a gauged non-linear sigma model for the interacting, disordered problem.
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