Dynamical failure of Turing patternsA. Manor and N. M. Shnerb
Department of Physics, Bar-Ilan University - Ramat-Gan 52900 Israel
received 14 September 2005; accepted in final form 30 March 2006
published online 14 April 2006
The emergence of stable disordered patterns in reactive systems on a spatially homogenous substrate is studied in the context of vegetation patterns in the semi-arid climatic zone. It is shown that reaction-diffusion systems that allow for Turing instability may exhibit heterogeneous "glassy" steady state with no characteristic wavelength if the diffusion rate associated with the slow reactant is very small. Upon decreasing the diffusion constant of the slow reactant three phases are identified: strong diffusion yields a stable homogenous phase, intermediate diffusion supports Turing (crystal like) patterns while in the slow-diffusion limit the glassy state is the generic stable solution. In this disordered phase the dynamics is of crucial importance, with strong differences between local and global initiation.
45.70.Qj - Pattern formation.
82.40.Ck - Pattern formation in reactions with diffusion, flow and heat transfer.
05.45.-a - Nonlinear dynamics and chaos.
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