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arXiv 1302.2499math.DSnlin.CDq-bio.PE
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具有一般非线性的反应扩散/捕食-被捕食模型中的周期和混沌行波斑图

Periodic and Chaotic Traveling Wave Patterns in Reaction-Diffusion/ Predator-Prey Models with General Nonlinearities

Stefan C. Mancas, Roy S. Choudhury

摘要:

研究了广义两种群捕食模型和两分量反应扩散方程的行波解。考虑了行波常微分方程(在通常的“空间”变量中)的不动点的稳定性。对于一般的功能形式的非线性猎物出生率/猎物死亡率或反应条款,一个霍普夫分岔发生在两个不同的临界值的行波速度。研究了五种不同非线性函数形式的后分岔动力学。在分岔是超临界的情况下,分岔后的行为产生稳定的周期轨道的行波常微分方程的空间变量。这些对应于完整偏微分方程的稳定周期波列。亚临界Hopf分岔在PDE波列中产生更复杂的分岔后动力学。在特殊情况下,亚临界分叉标志着结束的制度的稳定性,分叉后的行为在空间常微分方程是混乱的,对应于原来的PDE的波列是空间相干的,但有混沌的时间动力学。所有的模型进行了集成的数值研究后分岔动力学和混沌制度的特点是计算功率谱,自相关函数,分形维数。

英文摘要:

Traveling wavetrains in generalized two-species predator-prey models and two-component reaction-diffusion equations are considered. The stability of the fixed points of the traveling wave ODEs (in the usual "spatial" variable) is considered. For general functional forms of the nonlinear prey birthrate/prey deathrate or reaction terms, a Hopf bifurcation is shown to occur at two different critical values of the traveling wave speed. The post-bifurcation dynamics is investigated for five different functional forms of the nonlinearities. In cases where the bifurcation is supercritical, the post-bifurcation behaviour yields stable periodic orbits of the traveling-wave ODEs in the spatial variable. These correspond to stable periodic wavetrains of the full PDEs. Subcritical Hopf bifurcations yield more complex post-bifurcation dynamics in the PDE wavetrains. In special cases where the subcritical bifurcation marks the end of the regime of stability, the post-bifurcation behavior in the spatial ODEs is chaotic, corresponding to wavetrains of the original PDEs which are spatially coherent, but have chaotic temporal dynamics. All the models are integrated numerically to investigate the post-bifurcation dynamics and chaotic regimes are characterized by computing power spectra, autocorrelation functions, and fractal dimensions.

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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