On ergodic transformations that are both weakly mixing and uniformly rigid.
We prove that action of a semigroup on compact metric space by continuous selfmaps is strongly proximal if and only if action on is strongly proximal. As a consequence we prove that affine actions on certain compact convex subsets of finite-dimensional vector spaces are strongly proximal if and only if the action is proximal.
We show that for any cellular automaton (CA) ℤ²-action Φ on the space of all doubly infinite sequences with values in a finite set A, determined by an automaton rule , l,r ∈ ℤ, l ≤ r, and any Φ-invariant Borel probability measure, the directional entropy , v⃗= (x,y) ∈ ℝ², is bounded above by if and by in the opposite case, where , . We also show that in the class of permutative CA-actions the bounds are attained if the measure considered is uniform Bernoulli.