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arXiv 2101.03597math.APmath-phmath.MPphysics.flu-dyn
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可压缩Euler-Poisson方程具有大球对称初值的全局解

Global Solutions of the Compressible Euler-Poisson Equations with Large Initial Data of Spherical Symmetry

Gui-Qiang G. Chen, Lin He, Yong Wang, Difan Yuan

AI总结:

本文针对可压缩Euler-Poisson方程的大球对称初值问题,建立有限能量解的全局存在性,并证明在粘性消失极限下密度不会在原点形成delta测度集中。

摘要:

本文关注多维可压缩Euler-Poisson方程在具有大球对称初值条件下,对可压缩气体恒星和等离子体两者的有限能量解的全局存在性理论。主要挑战之一是波在径向向内传播至原点时增强,特别是在气体恒星的自洽引力场下。一个基本未解决的问题是全局解的密度是否在原点形成delta测度(即集中)。为解决此问题,我们发展了一种新方法来构造近似解,将其作为适当表述的可压缩Navier-Stokes-Poisson方程自由边界问题的解,并采用一类精心适配的退化密度依赖粘性项,从而能够严格证明近似解收敛到具有大球对称初值的可压缩Euler-Poisson方程对应的全局解。尽管密度在某一时刻可能在原点附近爆破,但已证明在所考虑的物理区域内,对于气体恒星和等离子体两者的可压缩Euler-Poisson方程的有限能量解,在粘性消失极限中不会形成时空中的delta测度(即集中)。

英文摘要:

We are concerned with a global existence theory for finite-energy solutions of the multidimensional Euler-Poisson equations for both compressible gaseous stars and plasmas with large initial data of spherical symmetry. One of the main challenges is the strengthening of waves as they move radially inward towards the origin, especially under the self-consistent gravitational field for gaseous stars. A fundamental unsolved problem is whether the density of the global solution forms a delta measure ({\it i.e.}, concentration) at the origin. To solve this problem, we develop a new approach for the construction of approximate solutions as the solutions of an appropriately formulated free boundary problem for the compressible Navier-Stokes-Poisson equations with a carefully adapted class of degenerate density-dependent viscosity terms, so that a rigorous convergence proof of the approximate solutions to the corresponding global solution of the compressible Euler-Poisson equations with large initial data of spherical symmetry can be obtained. Even though the density may blow up near the origin at a certain time, it is proved that no delta measure ({\it i.e.}, concentration) in space-time is formed in the vanishing viscosity limit for the finite-energy solutions of the compressible Euler-Poisson equations for both gaseous stars and plasmas in the physical regimes under consideration.

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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