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arXiv 2107.09573math.APmath.CA
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非柱形时变域中散度算子右逆的构造

Construction of a right inverse for the divergence in non-cylindrical time dependent domains

Olli Saari, Sebastian Schwarzacher

AI总结:

本文在空间Hölder正则、时间连续演化的非柱形域上构造了具有零边值的Bogovskij型散度算子稳定右逆,建立了正负阶Sobolev估计,并将其应用于时变域Navier--Stokes方程弱解的压力估计。

摘要:

我们在时空中的非柱形域上构造了散度算子的稳定右逆。假设这些区域在空间上是Hölder正则的,并且在时间上连续演化。该逆算子属于Bogovskij型,即它在边界上取零值。我们给出了关于时间变量和空间变量的正阶与负阶Sobolev空间中的估计。算子的正则性估计依赖于所假设的区域Hölder正则性。这些结果可以自然地与已知的Lipschitz域理论联系起来。作为一个应用,我们证明了时变域中Navier--Stokes方程的弱解和非常弱解的精化压力估计。

英文摘要:

We construct a stable right inverse for the divergence operator in non-cylindrical domains in space-time. The domains are assumed to be Hölder regular in space and evolve continuously in time. The inverse operator is of Bogovskij type, meaning that it attains zero boundary values. We provide estimates in Sobolev spaces of positive and negative order with respect to both time and space variables. The regularity estimates on the operator depend on the assumed Hölder regularity of the domain. The results can naturally be connected to the known theory for Lipschitz domains. As an application, we prove refined pressure estimates for weak and very weak solutions to Navier--Stokes equations in time dependent domains.

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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