Unbounded fluctuations in transport through an integrable cavity
  We derive a semiclassical scheme for the conductance through a rectangular cavity. The transmission amplitudes are expressed as a sum over families of trajectories rather than a sum over isolated trajectories. The contributing families are obtained from the evaluation of a finite number of continued fractions. We find that, contrary to the chaotic case, the conductance fluctuations increase with the incoming energy and the correlation function exhibits a singularity at the origin. 
Paul Pichaureau and Rodolfo A. Jalabert