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arXiv 1506.04071math.AP
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带非局部压力的多孔介质方程的有限和无限传播速度

Finite and infinite speed of propagation for porous medium equations with nonlocal pressure

Diana Stan, Félix del Teso, Juan Luis Vázquez

摘要:

本文研究了一个具有分数位压的多孔介质方程:$$ \partial_t u= \nabla \cdot (u^{m-1} \nabla p), \quad p=(-Δ)^{-s}u, $$对$m>1$,$0<s<1$和$u(x,t)\ge 0$ .该问题针对$x\in \mathbb{R}^N$、$N\geq 1$和$t>0$提出。初始数据$u(x,0)$被假定为具有紧支撑或在无穷远处快速衰减的有界函数。我们建立一类弱解的存在性,我们确定是否紧支持的属性是保守的时间依赖于参数$m$,从已知的$m=2$有限传播的结果。我们发现,当$m\in [1,2)$的问题有无限的传播速度,而对于$m\in [2,3)$它有有限的传播速度。换句话说,$m=2$是关于传播的临界指数。

英文摘要:

We study a porous medium equation with fractional potential pressure: $$ \partial_t u= \nabla \cdot (u^{m-1} \nabla p), \quad p=(-Δ)^{-s}u, $$ for $m>1$, $0<s<1$ and $u(x,t)\ge 0$. The problem is posed for $x\in \mathbb{R}^N$, $N\geq 1$, and $t>0$. The initial data $u(x,0)$ is assumed to be a bounded function with compact support or fast decay at infinity. We establish existence of a class of weak solutions for which we determine whether the property of compact support is conserved in time depending on the parameter $m$, starting from the result of finite propagation known for $m=2$. We find that when $m\in [1,2)$ the problem has infinite speed of propagation, while for $m\in [2,3)$ it has finite speed of propagation. In other words $m=2$ is critical exponent regarding propagation.

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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