Complex transitions to synchronization in delay-coupled networks of logistic maps

Cristina Masoller and Fatihcan M. Atay

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Submission date: 02. Jun. 2011
Pages: 16
published in: The European physical journal / D, 62 (2011) 1, p. 119-126 
DOI number (of the published article): 10.1140/epjd/e2011-10370-7
Bibtex
PACS-Numbers: 05.45.-a, 05.45.Xt, 89.75.-k, 89.75.Hc
Keywords and phrases: networks, Symbolic Dynamics, delay, chaos
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Abstract:
A network of delay-coupled logistic maps exhibits two different synchronization regimes, depending on the distribution of the coupling delay times. When the delays are homogeneous throughout the network, the network synchronizes to a time-dependent state [Atay et al., Phys. Rev. Lett. 92, 144101 (2004)], which may be periodic or chaotic depending on the delay; when the delays are sufficiently heterogeneous, the synchronization proceeds to a steady-state, which is unstable for the uncoupled map [Masoller and Marti, Phys. Rev. Lett. 94, 134102 (2005)]. Here we characterize the transition from time-dependent to steady-state synchronization as the width of the delay distribution increases. We also compare the two transitions to synchronization as the coupling strength increases. We use transition probabilities calculated via symbolic analysis and ordinal patterns. We find that, as the coupling strength increases, before the onset of steady-state synchronization the network splits into two clusters which are in anti-phase relation with each other. On the other hand, with increasing delay heterogeneity, no cluster formation is seen at the onset of steady-state synchronization; however, a rather complex unsynchronized state is detected, revealed by a diversity of transition probabilities in the network nodes.