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arXiv 2501.03574math.AP
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超临界Fujita方程的Liouville定理及其应用

A Liouville theorem for supercritical Fujita equation and its applications

Kelei Wang, Juncheng Wei, Ke Wu

AI总结:

本文证明了超临界Fujita方程古代解的Liouville定理,明确大尺度下接近ODE解的解必为ODE解,揭示ODE爆破的稳定性,并应用该定理刻画了弱解终时刻奇异集的分解结构与维数估计。

摘要:

我们证明了超临界Fujita方程\\[\partial_tu-\Delta u=|u|^{p-1}u, \quad -\infty <t<0, \quad p>\frac{n+2}{n-2}\\]古代解的Liouville定理:若解$u$在大尺度下接近ODE解$u_0(t):=(p-1)^{-\frac{1}{p-1}}(-t)^{-\frac{1}{p-1}}$,则它就是ODE解(即仅依赖于$t$)。这意味着该问题中ODE爆破具有稳定性。作为这些结果的应用,我们证明对合适的弱解,其终时刻的奇异集可分解为两部分:一部分是相对开的$(n-1)$-可求长集,特征为这些点处的切函数是两个常数$\pm(p-1)^{-\frac{1}{p-1}}$;另一部分是相对闭集,其Hausdorff维数不大于$n-\left[2\frac{p+1}{p-1}\right]-1$。

英文摘要:

We prove a Liouville theorem for ancient solutions to the supercritical Fujita equation \[\partial_tu-Δu=|u|^{p-1}u, \quad -\infty <t<0, \quad p>\frac{n+2}{n-2},\] which says if $u$ is close to the ODE solution $u_0(t):=(p-1)^{-\frac{1}{p-1}}(-t)^{-\frac{1}{p-1}}$ at large scales, then it is an ODE solution (i.e. it depends only on $t$). This implies a stability property for ODE blow ups in this problem. As an application of these results, we show that for a suitable weak solution, its singular set at the end time can be decomposed into two parts: one part is relatively open and $(n-1)$-rectifiable, and it is characterized by the property that tangent functions at these points are the two constants $\pm(p-1)^{-\frac{1}{p-1}}$; the other part is relatively closed and its Hausdorff dimension is not larger than $n-\left[2\frac{p+1}{p-1}\right]-1$.

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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