The statistics of diffusive flux
  We calculate the explicit probability distribution function for the flux between sites in a simple discrete time diffusive system composed of independent random walkers. We highlight some of the features of the distribution and we discuss its relation to the local instantaneous entropy production in the system. Our results are applicable both to equilibrium and non-equilibrium steady states as well as for certain time dependent situations. 
Alba Margarita Resendiz Antonio, Hernan Larralde