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arXiv 1104.3686math.AP
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时间非齐次KPP反应扩散方程的传播现象

Propagation phenomena for time heterogeneous KPP reaction-diffusion equations

Grégoire Nadin, Luca Rossi

摘要:

本文研究了非均匀反应扩散方程$\partial_t u -Δu = f(t,u)$,$x\in R^N$,$t\in\R$的传播现象,其中f=f(t,u)是KPP单稳非线性项,一般依赖于t.满足我们假设的一个典型f是f(t,u)=m(t)u(1-u),其中m有界且有正下确界.首先,我们证明了存在的广义过渡波(最近定义的Berestycki和哈默尔,沉)为一类给定的速度。作为这个结果的应用,我们得到了当f是关于t的随机平稳遍历函数时,随机跃迁波的存在性。最后,我们证明了柯西问题解的一些扩散性质。

英文摘要:

We investigate in this paper propagation phenomena for the heterogeneous reaction-diffusion equation $\partial_t u -Δu = f(t,u)$, $x\in R^N$, $t\in\R$, where f=f(t,u) is a KPP monostable nonlinearity which depends in a general way on t. A typical f which satisfies our hypotheses is f(t,u)=m(t) u(1-u), with m bounded and having positive infimum. We first prove the existence of generalized transition waves (recently defined by Berestycki and Hamel, Shen) for a given class of speeds. As an application of this result, we obtain the existence of random transition waves when f is a random stationary ergodic function with respect to t. Lastly, we prove some spreading properties for the solution of the Cauchy problem.

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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