Log-periodic oscillations for biased diffusion on random lattice

Random walks with a fixed bias direction on randomly diluted cubic lattices far above the percolation threshold exhibit log-periodic oscillations in the effective exponent versus time. A scaling argument accounts for the numerical results in the limit of large biases and small dilution and shows the importance of the interplay of these two ingredients in the generation of the log-periodicity. These results show that log-periodicity is the dominant effect compared to previous predictions of and reports on anomalous diffusion. (C) 1998 Elsevier Science B.V. All rights reserved.