On the spectrum of stochastic perturbations of the shift and Julia sets

Abstract

We extend the Killeen-Taylor study [Nonlinearity 13 (2000)] by investigating in different Banach spaces (l(alpha)(N), c(0)(N),c(N)) the point, continuous and residual spectra of stochastic perturbations of the shift operator associated to the stochastic adding machine in base 2 and in the Fibonacci base. For the base 2, the spectra are connected to the Julia set of a quadratic map. In the Fibonacci case, the spectrum is related to the Julia set of an endomorphism of C-2.