arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1709.07296math.APnlin.PSq-bio.CB
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通量受限的Keller-Segel模型中的行波和凝聚

Traveling Wave and Aggregation in a Flux-Limited Keller-Segel Model

Vincent Calvez, Benoît Perthame, Shugo Yasuda

摘要:

通量限制Keller-Segel(FLKS)模型是近年来从细菌趋化性动力学模型中发展起来的一个模型,它能更好地描述实验中观察到的细菌群体运动。最近,与动力学模型,一个新的不稳定形式主义已被发现有关的僵硬的趋化反应。这激发了我们基于带有种群增长项的FLKS模型研究趋化细胞种群动力学中的行波和聚集现象。我们的研究包括数值和理论的贡献。在数值部分,我们发现了各种各样的解决方案类型的一维FLKS模型除了标准的Fisher/KPP型行波。显著的结果是一个反直觉的后向行波,其中最初在稳定状态中饱和的种群密度在局部种群动力学中向不稳定状态过渡。出乎意料的是,我们还发现,后向行波解过渡到一个本地化的尖峰解决方案,增加趋化反应的刚度。在理论部分,我们得到了一个新的最小行进速度的解析公式,其中包括趋化漂移与复制/扩散的平衡作用的传播前沿。数值结果的前向传播速度仅略微偏离最小传播速度,除了局部化的尖峰解,即使对于向后的行波。我们还发现了大刚度极限下的单峰行波的一个分析解,它在一定的参数范围内是不稳定的。

英文摘要:

Flux-limited Keller-Segel (FLKS) model has been recently derived from kinetic transport models for bacterial chemotaxis and shown to represent better the collective movement observed experimentally. Recently, associated to the kinetic model, a new instability formalism has been discovered related to stiff chemotactic response. This motivates our study of traveling wave and aggregation in population dynamics of chemotactic cells based on the FLKS model with a population growth term. Our study includes both numerical and theoretical contributions. In the numerical part, we uncover a variety of solution types in the one-dimensional FLKS model additionally to standard Fisher/KPP type traveling wave. The remarkable result is a counter-intuitive backward traveling wave, where the population density initially saturated in a stable state transits toward an unstable state in the local population dynamics. Unexpectedly, we also find that the backward traveling wave solution transits to a localized spiky solution as increasing the stiffness of chemotactic response. In the theoretical part, we obtain a novel analytic formula for the minimum traveling speed which includes the counterbalancing effect of chemotactic drift vs. reproduction/diffusion in the propagating front. The front propagation speeds of numerical results only slightly deviate from the minimum traveling speeds, except for the localized spiky solutions, even for the backward traveling waves. We also discover an analytic solution of unimodal traveling wave in the large-stiffness limit, which is certainly unstable but exists in a certain range of parameters.

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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