Universal power spectra for the reverse bifurcation sequence

Many dynamical systems exhibit forward and reverse period-doubling bifurcation sequences, the latter being intrinsically noisy. Feigenbaum has predicted the amplitude of sharp spectral components in the forward sequence from universality arguments. In the same spirit we derive the approximate form of the broad band features in the reverse sequence. Our results give a power-law behavior of the integrated noise spectrum similar to that recently reported by Huberman and Zisook.