The synchronization transition between two coupled replicas of
spatio-temporal chaotic systems in 2+1 dimensions is studied as a phase
transition into an absorbing state - the synchronized state. Confirming the
scenario drawn in 1+1 dimensional systems, the transition is found to belong to
two different universality classes - Multiplicative Noise (MN) and Directed
Percolation (DP) - depending on the linear or nonlinear character of damage
spreading occurring in the coupled systems. By comparing coupled map lattice
with two different stochastic models, accurate numerical estimates for MN in
2+1 dimensions are obtained. Finally, aiming to pave the way for future
experimental studies, slightly non-identical replicas have been considered. It
is shown that the presence of small differences between the dynamics of the two
replicas acts as an external field in the context of absorbing phase
transitions, and can be characterized in terms of a suitable critical exponent.Comment: Submitted to Journal of Statistical Mechanics: Theory and Experimen
