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arXiv 1002.2094math.AP
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具有梯度吸收和临界指数的非线性抛物型方程的渐近性

Asymptotic Behaviour of a Nonlinear Parabolic Equation with Gradient Absorption and Critical Exponent

Razvan Gabriel Iagar, Philippe Laurençot, Juan Luis Vázquez

摘要:

本文研究了具有非线性扩散和梯度吸收的发展方程$$ \partial_t u - Δ_p u + |\nabla u|^q=0 . $$解的大时间行为。我们考虑了在非负紧支集的初值条件下对$x\in \real^N$和t>0所提出的问题。我们取指数p>2,这对应于慢p-Laplacian扩散。本文的主要特点是指数q取临界值q=p-1,这导致有趣的渐近性。这是由于在这种情况下,哈密尔顿-雅可比项$ |\nabla u|^q$和扩散项$Δ_p u$在很长时间内具有相似的大小。在本文中进行的研究表明,一个微妙的渐近平衡的发生,使大的时间行为的解决方案是由一个合适的自相似解决方案的Hamilton-Jacobi方程$|\nabla W|^{p-1}=W$,对数时间校正的重新缩放版本。渐近重标度剖面是一种顶部有尖点的沙堆,它与空间维数无关。

英文摘要:

We study the large-time behaviour of the solutions of the evolution equation involving nonlinear diffusion and gradient absorption, $$ \partial_t u - Δ_p u + |\nabla u|^q=0 . $$ We consider the problem posed for $x\in \real^N$ and t>0 with nonnegative and compactly supported initial data. We take the exponent p>2 which corresponds to slow p-Laplacian diffusion. The main feature of the paper is that the exponent q takes the critical value q=p-1 which leads to interesting asymptotics. This is due to the fact that in this case both the Hamilton-Jacobi term $ |\nabla u|^q$ and the diffusive term $Δ_p u$ have a similar size for large times. The study performed in this paper shows that a delicate asymptotic equilibrium happens, so that the large-time behaviour of the solutions is described by a rescaled version of a suitable self-similar solution of the Hamilton-Jacobi equation $|\nabla W|^{p-1}=W$, with logarithmic time corrections. The asymptotic rescaled profile is a kind of sandpile with a cusp on top, and it is independent of the space dimension.

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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