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arXiv 2008.07756math.AP
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具有不定常阻尼的可压缩Euler方程的奇异性形成

Singularity formation for compressible Euler equations with time-dependent damping

Ying Sui, Huimin Yu

摘要:

本文考虑一维空间中具有不定常阻尼\frac{\a}{(1+t)^λ} u的可压缩Euler方程。通过构造光滑解的“解耦”Riccati型方程,给出了经典解在有限时间内崩溃的充分条件.作为一个副产品,我们表明,衍生物爆炸,有点像冲击波的形成,如果衍生物的初始数据是适当的大点,即使当阻尼系数以代数增长率无穷大。我们分别研究了λ \neq 1和λ=1的情形,并且我们的结果对解的大小和初始Riemann不变量的正性/单调性没有限制.此外,对于1<γ<3,我们提供了任意经典解的密度的不定常下界,而无需对初始数据作任何额外的假设。

英文摘要:

In this paper, we consider the compressible Euler equations with time-dependent damping \frac{\a}{(1+t)^λ}u in one space dimension. By constructing 'decoupled' Riccati type equations for smooth solutions, we provide some sufficient conditions under which the classical solutions must break down in finite time. As a byproduct, we show that the derivatives blow up, somewhat like the formation of shock wave, if the derivatives of initial data are appropriately large at a point even when the damping coefficient goes to infinity with a algebraic growth rate. We study the case λ\neq1 and λ=1 respectively, moreover, our results have no restrictions on the size of solutions and the positivity/monotonicity of the initial Riemann invariants. In addition, for 1<γ<3 we provide time-dependent lower bounds on density for arbitrary classical solutions, without any additional assumptions on the initial data.

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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