Some Ergodic Properties of Invertible Cellular Automata

Abstract

In this paper we consider invertible one-dimensional linear cellular automata (CA hereafter) defined on a finite alphabet of cardinality $p^k$, i.e. the maps $T_{f[l,r]}:\mathbb{Z}^{\mathbb{Z}}_{p^k}\to\mathbb{Z}^{\mathbb{Z}}_{p^k}$ which are given by $T_{f[l,r]}(x) = (y_n)_{n=-\infty}^{\infty} $, $y_{n} = f(x_{n+l}, ..., x_{n+r}) =\overset{r}{\underset{i=l}{\sum}}\lambda _{i}x_{n+i}(\text{mod} p^k)$, $x=(x_n)_{n=-\infty}^{\infty}\in \mathbb{Z}^{\mathbb{Z}}_{p^k}$ and $f:\mathbb{Z}^{r-l+1}_{p^k}\to \mathbb{Z}_{p^k}$, over the ring $\mathbb{Z}_{p^k}$ $(k \geq 2$ and $p$ is a prime number), where $gcd(p,\lambda_r)=1$ and $p| \lambda_i$ for all $i \neq r $ (or $gcd(p, \lambda_l)=1$ and $p|\lambda_i$ for all $i\neq l$). Under some assumptions we prove that any right (left) permutative, invertible one-dimensional linear CA $T_{f[l,r]}$ and its inverse are strong mixing. We also prove that any right(left) permutative, invertible one-dimensional linear CA is Bernoulli automorphism without making use of the natural extension previously used in the literature.