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arXiv 1702.07515math.AP
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关于Parker问题的动力稳定性和不稳定性

On the Dynamical Stability and Instability of Parker Problem

Fei Jiang, Song Jiang

摘要:

研究了在边界上流体速度无滑移的垂直条形区域中,具有零电阻率的三维可压缩等熵粘性磁流体动力学系统在修正引力作用下的摄动问题,着重讨论了(平衡)磁场通过无滑移边界条件的稳定作用.我们表明,有一个判别式$Ξ$,取决于已知的物理参数,稳定性/不稳定性的扰动问题。更确切地说,如果是$Ξ<0$,则扰动问题是不稳定的,即,Parker不稳定性发生,而如果$Ξ>0$和初始扰动满足某些关系,则存在随时间代数衰减到零的全局(扰动)解,即,帕克不稳定性不会发生。本文的稳定性结果揭示了磁场通过无滑移边界条件的稳定作用以及边界条件对Parker不稳定性的重要性,并证明了足够强的磁场可以防止Parker不稳定性的发生。此外,基于不稳定性的结果,我们进一步严格验证了帕克不稳定性Schwarzschild或Tserkovnikov的不稳定性条件的意义上的阿达玛水平周期域。

英文摘要:

We investigate a perturbation problem for the three-dimensional compressible isentropic viscous magnetohydrodynamic system with zero resistivity in the presence of a modified gravitational force in a vertical strip domain in which the velocity of the fluid is non-slip on the boundary, and focus on the stabilizing effect of the (equilibrium) magnetic field through the non-slip boundary condition. We show that there is a discriminant $Ξ$, depending on the known physical parameters, for the stability/instability of the perturbation problem. More precisely, if $Ξ<0$, then the perturbation problem is unstable, i.e., the Parker instability occurs, while if $Ξ>0$ and the initial perturbation satisfies some relations, then there exists a global (perturbation) solution which decays algebraically to zero in time, i.e., the Parker instability does not happen. The stability results in this paper reveal the stabilizing effect of the magnetic field through the non-slip boundary condition and the importance of boundary conditions upon the Parker instability, and demonstrate that a sufficiently strong magnetic field can prevent the Parker instability from occurring. In addition, based on the instability results, we further rigorously verify the Parker instability under Schwarzschild's or Tserkovnikov's instability conditions in the sense of Hadamard for a horizontally periodic domain.

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