Exponential Deviations and Hölder Continuity for Moving-Law Mixed Cocycles

Abstract

We study mixed random-quasiperiodic cocycles whose one-step laws evolve along an ergodic environment. Under mixed-base ergodicity, bounded logarithmic growth, and stationary-value uniqueness, which we characterize by relative quasi-irreducibility, we prove exponential quenched deviations for finite-time directional growth. A renewal example shows that, in general ergodic environments, annealed exponential deviations can fail despite quenched exponential concentration. This obstruction motivates us to consider a fixed finite-state irreducible aperiodic Markov environment, where we establish annealed exponential deviation estimates uniform over a relative neighborhood of a reference sampling kernel in the bounded mixed-base-ergodic class at each fixed tolerance. These estimates yield local Hölder continuity of the maximal Lyapunov exponent near a stationary-value-unique kernel with a simple top exponent. Under common matrix and inverse bounds, the continuity applies to synchronized Wasserstein perturbations with fixed translation marginals and continuous matrix fields, or to ordinary Wasserstein perturbations with uniform Hölder regularity in the phase. As an application, suitable frequency-support and noise-nondegeneracy conditions yield Hölder energy dependence for moving-law Schrödinger cocycles with continuous potentials.