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arXiv 2407.04498math.AP
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$\u211d^3$中广义趋化-Navier-Stokes系统的全局动力学

Global dynamics for the generalized chemotaxis-Navier-Stokes system in $\mathbb{R}^3$

Qingyou He, Ling-Yun Shou, Leyun Wu

AI总结:

本文研究$\mathbb{R}^3$中广义趋化-Navier-Stokes系统的全局动力学,证明了强解的爆破准则,并在不同耗散指数条件下建立了全局适定性与最优时间衰减率。

摘要:

我们考虑在$\mathbb{R}^3$中具有广义流体耗散的趋化-Navier-Stokes系统:该方程组描述了悬浮于水流中的游动细菌或枯草芽孢杆菌的运动。首先,我们证明了Cauchy问题强解的一些爆破准则,包括Prodi-Serrin型准则($\alpha>\frac{3}{4}$)和Beirão da Veiga型准则($\alpha>\frac{1}{2}$)。然后,我们验证了当$\alpha\geq \frac{5}{4}$时,对于任意大的初始流体速度和细菌密度,强解的全局存在性与唯一性。此外,在$\frac{3}{4}<\alpha<\frac{5}{4}$的情形下,如果初始数据的$L^2$-范数足够小,我们建立了全局解的一致正则性估计和最优时间衰减率。据我们所知,这是关于具有可能大振荡的趋化-Navier-Stokes方程强解的全局存在性和长时间行为的首个结果。

英文摘要:

We consider the chemotaxis-Navier-Stokes system with generalized fluid dissipation in $\mathbb{R}^3$: \begin{eqnarray*} \begin{cases} \partial_t n+u\cdot \nabla n=Δn- \nabla \cdot (χ(c)n \nabla c),\\ \partial_t c+u \cdot \nabla c=Δc-nf(c),\\ \partial_t u +u \cdot \nabla u+\nabla P=-(-Δ)^αu-n\nabla ϕ,\\ \nabla \cdot u=0, \end{cases} \end{eqnarray*} which describes the motion of swimming bacteria or bacillus subtilis suspended to water flows. First, we prove some blow-up criteria of strong solutions to the Cauchy problem, including the Prodi-Serrin type criterion ($α>\frac{3}{4}$) and the Beir${\rm\tilde{a}}$o da Veiga type criterion $(α>\frac{1}{2})$. Then, we verify the global existence and uniqueness of strong solutions for arbitrarily large initial fluid velocity and bacteria density for $α\geq \frac{5}{4}$. Furthermore, in the scenario of $\frac{3}{4}<α<\frac{5}{4}$, we establish uniform regularity estimates and optimal time-decay rates of global solutions if the $L^2$-norm of initial data is small. To our knowledge, this is the first result concerning the global existence and large-time behavior of strong solutions for the chemotaxis-Navier-Stokes equations with possibly large 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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