Ergodicity of PCA : equivalence between spatial and temporal mixing conditions

For a general attractive Probabilistic Cellular Automata on S-Zd, we prove that the (time-) convergence towards equilibrium of this Markovian parallel dynamics, exponentially fast in the uniform norm, is equivalent to a condition (A). This condition means the exponential decay of the influence from...

Full description

Bibliographic Details
Main Author: Louis, Pierre-Yves
Format: Others
Language:English
Published: Universität Potsdam 2004
Subjects:
Online Access:http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6589
http://opus.kobv.de/ubp/volltexte/2006/658/
Description
Summary:For a general attractive Probabilistic Cellular Automata on S-Zd, we prove that the (time-) convergence towards equilibrium of this Markovian parallel dynamics, exponentially fast in the uniform norm, is equivalent to a condition (A). This condition means the exponential decay of the influence from the boundary for the invariant measures of the system restricted to finite boxes. For a class of reversible PCA dynamics on {1,+1}(Zd), wit a naturally associated Gibbsian potential rho, we prove that a (spatial-) weak mixing condition (WM) for rho implies the validity of the assumption (A); thus exponential (time-) ergodicity of these dynamics towards the unique Gibbs measure associated to rho hods. On some particular examples we state that exponential ergodicity holds as soon as there is no phase transition.