Shape of the ground state energy density of Hill's equation with nice   Gaussian potential
  Consider Hill's operator Q = -D^2 + q(x) in which the potential q(x) is an almost surely continuous and rotation invariant Gaussian process on the circle of perimeter one. Viewing the classical Riccati map as a change of measure, we establish functional integral formulas for the probability density function of the ground state energy and also determine the density's shape. 
Jose A. Ramirez, Brian Rider