We show that Brownian motion of a one-dimensional domain wall in a large but finite system yields a $\omega^{ -3/2}$ power spectrum. This is successfully applied to the totally asymmetric simple exclusion process (TASEP) with open boundaries. An excellent agreement between our theory and numerical results is obtained in a frequency range where the domain wall motion dominates and discreteness of the system is not effective.
Categories: cond-mat.stat-mech