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arXiv 1201.6352math.DScs.NAmath.NAnlin.CDq-bio.NC
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FitzHugh-Nagumo方程的同宿轨道:完整系统中的分岔

Homoclinic Orbits of the FitzHugh-Nagumo Equation: Bifurcations in the Full System

Cornell University(康奈尔大学)

John Guckenheimer, Christian Kuehn

AI总结:

本文从快慢动力系统角度研究FitzHugh-Nagumo方程的波前解,通过数值方法揭示参数空间中同宿分岔曲线的急转弯现象,并利用几何模型预测多脉冲同宿轨道和周期轨道。

摘要:

本文从快慢动力系统的角度研究FitzHugh-Nagumo方程的行波解。这些解是依赖于FitzHugh-Nagumo模型系统参数和波速的三维向量场的同宿轨道。Champneys等人[A.R. Champneys, V. Kirk, E. Knobloch, B.E. Oldeman, and J. Sneyd, When Shilnikov meets Hopf in excitable systems, SIAM Journal of Applied Dynamical Systems, 6(4), 2007]在二维参数空间中观察到同宿分岔曲线的急转弯。本文通过数值方法证明,这些转弯位于参数空间中两条曲线的交点附近,这两条曲线确定了三维向量场不变流形的非横截相交。可视化了相空间中的相关不变流形。受数值研究启发的几何模型展示了同宿分岔曲线的急转弯,并对FitzHugh-Nagumo模型中尚未解析的多脉冲同宿轨道、同宿轨道和周期轨道给出了定量预测。进一步的观察涉及canard爆炸和混合模式振荡的存在性。

英文摘要:

This paper investigates travelling wave solutions of the FitzHugh-Nagumo equation from the viewpoint of fast-slow dynamical systems. These solutions are homoclinic orbits of a three dimensional vector field depending upon system parameters of the FitzHugh-Nagumo model and the wave speed. Champneys et al. [A.R. Champneys, V. Kirk, E. Knobloch, B.E. Oldeman, and J. Sneyd, When Shilnikov meets Hopf in excitable systems, SIAM Journal of Applied Dynamical Systems, 6(4), 2007] observed sharp turns in the curves of homoclinic bifurcations in a two dimensional parameter space. This paper demonstrates numerically that these turns are located close to the intersection of two curves in the parameter space that locate non-transversal intersections of invariant manifolds of the three dimensional vector field. The relevant invariant manifolds in phase space are visualized. A geometrical model inspired by the numerical studies displays the sharp turns of the homoclinic bifurcations curves and yields quantitative predictions about multi-pulse and homoclinic orbits and periodic orbits that have not been resolved in the FitzHugh-Nagumo model. Further observations address the existence of canard explosions and mixed-mode oscillations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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