Hall effect in percolating systems

The interpenetrating-network model that Bergman has proposed for the Hall effect in a percolating system is discussed, and it is shown that it gives incorrect exponents in the high-dimensionality limit, because a relevant variable has been excluded. A more general model is proposed which remedies this fault. Simulations of cubic lattices up to L=20 give an estimate for the exponent which describes the divergence of the Hall coefficient at pc:g=0.