1/f noise in spatially extended systems with order-disorder phase transitions

Noise power spectra in spatially extended dynamical systems are investigated, using as a model the Complex Ginzburg-Landau equation with a stochastic term. Analytical and numerical investigations show that the temporal noise spectra are of 1/f^a form, where a=2-D/2 with D the spatial dimension of the system. This suggests that nonequilibrium order-disorder phase transitions may play a role for the universally observed 1/f noise.