Ricerc@Sapienza

Cellular Automata are discrete--time dynamical systems on a
spatially extended discrete space which
provide paradigmatic examples of
nonlinear phenomena.
Their stochastic generalizations, i.e.,
Probabilistic Cellular Automata,
are discrete time Markov chains
on lattice with finite single--cell states whose
distinguishing feature is the \textit{parallel} character of the updating rule.
We review the some of the results obtained about the metastable
behavior of Probabilistic Cellular Automata and we try to
point out difficulties and peculiarities with respect to
standard Statistical Mechanics Lattice models.