Exact density of states of a two-dimensional electron gas in a strong   magnetic field and a long-range correlated random potential
  We derive an exact result for the averaged Feynman propagator and the corresponding density of states of an electron in two dimensions in a perpendicular homogeneous magnetic field and a Gaussian random potential with long-range spatial correlations described by a quadratic correlation function. 
Lothar Spies (1), Walter Apel (2), and Bernhard Kramer (1) ((1) U   Hamburg, (2) PTB Braunschweig, Germany )