Ergodic properties of certain surjective cellular automata
Tóm tắt
We consider one-dimensional cellular automata, i.e. the mapsT:P
ℤ
→P
ℤ
(P is a finite set with more than one element) which are given by (Tx)
i
=F(x
i+l
, ...,x
i+r
),x=(x
i
)∈ℤ∈P
ℤ
for some integersl≤r and a mappingF∶P
r−l+1→P. We prove that ifF is right- (left-) permutative (in Hedlund's terminology) and 0≤l0 andT is surjective, then the natural extension of the system (P
ℤ
, ℬ, μ,T) is aK-automorphism. We also prove that the shift ℤ2-action on a two-dimensional subshift of finite type canonically associated with the cellular automatonT is mixing, ifF is both right and left permutative. These results answer some questions raised in [SR].