Reducibility of nonlinear almost periodic systems of difference equations on an infinite-dimensional torus

Abstract

Sufficient conditions of reducibility of the nonlinear system of difference equations $x(t + 1) = x(t) + \omega + P(x(t), t) + \lambda$, to the system $y(t + 1) = y(t) + \omega$ are found; here, $x, \omega, \lambda \in \textbf{m}$, and the infinite-dimensional vector function $P(x(t),t)$ is $2\pi t$ - periodic in $x_i\; (i = 1,2,...)$ and almost periodic in $t$ with the frequency basis $\alpha$.