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arXiv 1901.04798math.AP
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等熵Euler方程组的半流解

Solution semiflow to the isentropic Euler system

Dominic Breit, Eduard Feireisl, Martina Hofmanova

摘要:

多维等熵欧拉方程组是极不适定的,这一点已为人们所熟知.即使某些光滑的初始数据会产生无穷多个解,所有可用的选择准则都不能确保全局存在性和唯一性。基于马尔可夫半群理论的思想,我们提出了一种不同的方法来证明这个系统的适定性:我们证明了Borel可测解半流的存在性。为此,我们引入了耗散解的概念,它被理解为基本状态变量-质量密度,线性动量和能量-在一个合适的相空间中的不定常的轨迹。偏微分方程的基本系统在广义上是满足的。解半流具有标准半群性质,只要强解存在,解与强解一致。此外,它们在所有耗散解中使能量最小化(使能量耗散最大化)。

英文摘要:

It is nowadays well understood that the multidimensional isentropic Euler system is desperately ill--posed. Even certain smooth initial data give rise to infinitely many solutions and all available selection criteria fail to ensure both global existence and uniqueness. We propose a different approach to well--posedness of this system based on ideas from the theory of Markov semigroups: we show the existence of a Borel measurable solution semiflow. To this end, we introduce a notion of dissipative solution which is understood as time dependent trajectories of the basic state variables - the mass density, the linear momentum, and the energy - in a suitable phase space. The underlying system of PDEs is satisfied in a generalized sense. The solution semiflow enjoys the standard semigroup property and the solutions coincide with the strong solutions as long as the latter exist. Moreover, they minimize the energy (maximize the energy dissipation) among all dissipative solutions.

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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