Mixed-mode chimera states in pendula networks

Autor: P. Ebrahimzadeh, M. Schiek, Y. Maistrenko
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Chaos 32(10), 103118-(2022). doi:10.1063/5.0103071
DOI: 10.1063/5.0103071
Popis: We report the emergence of peculiar chimera states in networks of identical pendula with global phase-lagged coupling. The states reported include both rotating and quiescent modes, i.e., with non-zero and zero average frequencies. This kind of mixed-mode chimeras may be interpreted as images of bump states known in neuroscience in the context of modeling the working memory. We illustrate this striking phenomenon for a network of 𝑁=100 coupled pendula, followed by a detailed description of the minimal non-trivial case of 𝑁=3. Parameter regions for five characteristic types of the system behavior are identified, which consist of two mixed-mode chimeras with one and two rotating pendula, classical weak chimera with all three pendula rotating, synchronous rotation, and quiescent state. The network dynamics is multistable: up to four of the states can coexist in the system phase state as demonstrated through the basins of attraction. The analysis suggests that the robust mixed-mode chimera states can generically describe the complex dynamics of diverse pendula-like systems widespread in nature.Chimera states generally refer to spatiotemporal patterns in networks of identical or close to identical oscillators, in which a group of oscillators is synchronized and the other group is asynchronous. For networks composed of Kuramoto oscillators with inertia, chimera states are manifested in the form of solitary states in which one or a few oscillators split off from the main synchronized cluster and start to rotate with a different average frequency. Chimeras of this kind include rotational modes, and their frequencies are determined by the system parameters. In networks of excitable elements, such as neurons, in contrary, chimeric spatiotemporal patterns typically arise in the form of bump states, where active spiking neurons (large amplitude) coexist with quiescent (subthreshold) ones. The bump states are created due to the competition mechanism between attractive and repulsive couplings, which suppresses the quiescent group. Then, the pendulum network can be viewed as a model bringing together the properties of the Kuramoto oscillators with inertia and the excitable theta neuron model, for which we show the emergence of mixed-mode chimeras with non-zero and zero average frequencies of individual oscillators from different groups.
Databáze: OpenAIRE
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