Nonlinear waves in a quintic FitzHugh–Nagumo model with cross diffusion: Fronts, pulses, and wave trains
| Autor: | Klaus Kassner, Werner Horsthemke, E. P. Zemskov, Mikhail A Tsyganov |
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| Rok vydání: | 2021 |
| Předmět: |
Physics
Bistability Cross diffusion Applied Mathematics Mathematical analysis Front (oceanography) General Physics and Astronomy Statistical and Nonlinear Physics Model parameters 01 natural sciences 010305 fluids & plasmas Quintic function Pulse (physics) Nonlinear system 0103 physical sciences FitzHugh–Nagumo model 010306 general physics Mathematical Physics |
| Zdroj: | Chaos: An Interdisciplinary Journal of Nonlinear Science. 31:033141 |
| ISSN: | 1089-7682 1054-1500 |
| Popis: | We study a tristable piecewise-linear reaction-diffusion system, which approximates a quintic FitzHugh-Nagumo model, with linear cross-diffusion terms of opposite signs. Basic nonlinear waves with oscillatory tails, namely, fronts, pulses, and wave trains, are described. The analytical construction of these waves is based on the results for the bistable case [Zemskov et al., Phys. Rev. E 77, 036219 (2008) and Phys. Rev. E 95, 012203 (2017) for fronts and for pulses and wave trains, respectively]. In addition, these constructions allow us to describe novel waves that are specific to the tristable system. Most interesting is the pulse solution with a zigzag-shaped profile, the bright-dark pulse, in analogy with optical solitons of similar shapes. Numerical simulations indicate that this wave can be stable in the system with asymmetric thresholds; there are no stable bright-dark pulses when the thresholds are symmetric. In the latter case, the pulse splits up into a tristable front and a bistable one that propagate with different speeds. This phenomenon is related to a specific feature of the wave behavior in the tristable system, the multiwave regime of propagation, i.e., the coexistence of several waves with different profile shapes and propagation speeds at the same values of the model parameters. |
| Databáze: | OpenAIRE |
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