966 research outputs found
Synchronization in driven versus autonomous coupled chaotic maps
The phenomenon of synchronization occurring in a locally coupled map lattice
subject to an external drive is compared to the synchronization process in an
autonomous coupled map system with similar local couplings plus a global
interaction. It is shown that chaotic synchronized states in both systems are
equivalent, but the collective states arising after the chaotic synchronized
state becomes unstable can be different in these two systems. It is found that
the external drive induces chaotic synchronization as well as synchronization
of unstable periodic orbits of the local dynamics in the driven lattice. On the
other hand, the addition of a global interaction in the autonomous system
allows for chaotic synchronization that is not possible in a large coupled map
system possessing only local couplings.Comment: 4 pages, 3 figs, accepted in Phys. Rev.
Random global coupling induces synchronization and nontrivial collective behavior in networks of chaotic maps
The phenomena of synchronization and nontrivial collective behavior are
studied in a model of coupled chaotic maps with random global coupling. The
mean field of the system is coupled to a fraction of elements randomly chosen
at any given time. It is shown that the reinjection of the mean field to a
fraction of randomly selected elements can induce synchronization and
nontrivial collective behavior in the system. The regions where these
collective states emerge on the space of parameters of the system are
calculated.Comment: 2 pages, 2 figs, accepted in The European Physical Journa
Phase growth in bistable systems with impurities
A system of coupled chaotic bistable maps on a lattice with randomly
distributed impurities is investigated as a model for studying the phenomenon
of phase growth in nonuniform media. The statistical properties of the system
are characterized by means of the average size of spatial domains of equivalent
spin variables that define the phases. It is found that the rate at which phase
domains grow becomes smaller when impurities are present and that the average
size of the resulting domains in the inhomogeneous state of the system
decreases when the density of impurities is increased. The phase diagram
showing regions where homogeneous, heterogeneous, and chessboard patterns occur
on the space of parameters of the system is obtained. A critical boundary that
separates the regime of slow growth of domains from the regime of fast growth
in the heterogeneous region of the phase diagram is calculated. The transition
between these two growth regimes is explained in terms of the stability
properties of the local phase configurations. Our results show that the
inclusion of spatial inhomogeneities can be used as a control mechanism for the
size and growth velocity of phase domains forming in spatiotemporal systems.Comment: 7 pages, 12 figure
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