Long-time behaviour of classical diffusion in a disordered lattice

The long-time behaviour of classical diffusion of a particle in a randomly interrupted medium is studied. The probability of finding a particle at position x=0 in d-dimensional space if initially it was at x=0 is shown to decay exponentially as P(t)-P(t= infinity ) approximately exp(-ct d (d+2)/) below the percolation threshold due to localisation.