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arXiv 2012.15848math.AP
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半空间中间歇初值下Navier-Stokes方程的全局弱解

Global weak solutions of the Navier-Stokes equations for intermittent initial data in half-space

Zachary Bradshaw, Igor Kukavica, Wojciech S. Ożański

AI总结:

本文在半空间中针对允许间歇性空间增长的初值,利用新的加权先验估计和压力估计证明了Navier-Stokes方程全局弱解的存在性、最终正则性,并构造了全局离散自相似解。

摘要:

我们证明了不可压缩Navier-Stokes方程在半空间 $\mathbb{R}^3_+$ 中存在全局时间弱解,其初值属于一个加权空间,该空间允许非均匀局部平方可积函数以间歇意义在空间无穷远处增长。初值空间建立在立方体上,其边长 $R$ 与到原点的距离成正比,并且数据的平方积分允许按 $R$ 的幂次增长。该存在性通过加权空间中的一个新的先验估计和稳定性结果以及新的压力估计获得。此外,对于满足 $t>c_1|x|^2 + c_2$ 的 $(x,t)$,其中 $c_1,c_2>0$,我们证明了一大类初值 $u_0$ 的此类弱解直到边界的最终正则性,且 $c_1$ 可任意小。作为存在性定理的一个应用,我们构造了全局离散自相似解,从而将半空间上的理论推广到与全空间相同的普遍性。

英文摘要:

We prove existence of global-in-time weak solutions of the incompressible Navier-Stokes equations in the half-space $\mathbb{R}^3_+$ with initial data in a weighted space that allow non-uniformly locally square integrable functions that grow at spatial infinity in an intermittent sense. The space for initial data is built on cubes whose sides $R$ are proportional to the distance to the origin and the square integral of the data is allowed to grow as a power of $R$. The existence is obtained via a new a priori estimate and stability result in the weighted space, as well as new pressure estimates. Also, we prove eventual regularity of such weak solutions, up to the boundary, for $(x,t)$ satisfying $t>c_1|x|^2 + c_2$, where $c_1,c_2>0$, for a large class of initial data $u_0$, with $c_1$ arbitrarily small. As an application of the existence theorem, we construct global discretely self-similar solutions, thus extending the theory on the half-space to the same generality as the whole space.

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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