DOUBLE UNIVERSALITY OF 1 F NOISE PERCOLATION-LIKE EXPONENT IN SYSTEMSWITH EXPONENTIALLY WIDE SPECTRUM OF RESISTANCES/

Theory and numerical simulations of 1/f noise in random networks in wh ich bonds take resistances r similar to exp(-lambda x), where x is a r andom variable and lambda much greater than 1 are presented. For micro scopic noise generating mechanism which obeys the form of {6 delta r(2 )}similar to r(2+theta), it is shown that the overall noise intensity of the network is given by C-e similar to lambda(m) exp(-lambda theta x(c)), where 1 - x(c) is the percolation threshold. In the range 0 les s than or equal to theta < 2 exponent m is ''double universal'', i.e. it is independent of the lattice geometry and of microscopic noise gen erating mechanism. Numerical simulations give m congruent to 2.5.