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arXiv 1208.3732math.AP
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Nash-Moser定理在带引力的一维可压缩Euler方程光滑解中的应用

An Application of Nash-Moser Theorem to Smooth Solutions of One-Dimensional Compressible Euler Equation with Gravity

Cheng-Hsiung Hsu, Song-Sun Lin, Tetu Makino, Chi-Ru Yang

摘要:

本文研究由可压缩欧拉方程控制的多变气体的一维运动。常重力作用下的半空间问题给出了一个有自由边界与真空接触的平衡点,在这个平衡点上的线性化近似给出了时间周期解。但是证明长时间真解的存在性是不容易的,对于长时间真解,时间周期解是第一近似。这种情况与没有重力的自由运动问题相反。这是由于在求解拟线性双曲型方程时,由于与真空接触而产生的能量损失,使得通常的迭代法不能使用。有趣的是,该方程可以转化为高维空间上的非线性波动方程,对于高维空间,大于4的空间维数与原始一维问题的绝热指数有关。我们试图找到一个家庭的解决方案扩大了一个小参数。应用Nash-Moser理论,我们证明了这一扩展,Nash-Moser理论的应用是克服损失的麻烦所必需的,而证明其适用性需要对问题进行非常细致的分析。

英文摘要:

We study one-dimensional motions of polytropic gas governed by the compressible Euler equations. The problem on the half space under a constant gravity gives an equilibrium which has free boundary touching the vacuum and the linearized approximation at this equilibrium gives time periodic solutions. But it is not easy to justify the existence of long-time true solutions for which this time periodic solution is the first approximation. The situation is in contrast to the problem of free motions without gravity. The reason is that the usual iteration method for quasilinear hyperbolic problem cannot be used because of the loss of regularities which causes from the touch with the vacuum. Interestingly, the equation can be transformed to a nonlinear wave equation on a higher dimensional space, for which the space dimension, being larger than 4, is related to the adiabatic exponent of the original one-dimensional problem. We try to find a family of solutions expanded by a small parameter. Applying the Nash-Moser theory, we justify this expansion.The application of the Nash-Moser theory is necessary for the sake of conquest of the trouble with loss of regularities, and the justification of the applicability requires a very delicate analysis of the problem.

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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