Nonlinear Analysis ( IF 1.3 ) Pub Date : 2021-06-04 , DOI: 10.1016/j.na.2021.112416 Jérôme Coville
In this article, we analyse the non-local model: where is a positive continuous dispersal kernel and is a heterogeneous KPP type non-linearity describing the growth rate of the population. The ecological niche of the population is assumed to be bounded (i.e. outside a compact set, the environment is assumed to be lethal for the population) and shifted through time at a constant speed . For compactly supported dispersal kernels , assuming that for the population survive, we prove that there exist critical speeds and such that for all then the population will survive and will perish when or . To derive these results we first obtain an optimal persistence criteria depending of the speed for non local problem with a drift term. Namely, we prove that for a positive speed the population persists if and only if the generalised principal eigenvalue of the linear problem is negative. is a spectral quantity that we defined in the spirit of the generalised first eigenvalue of an elliptic operator. The speeds and are then obtained through a fine analysis of the properties of with respect to . In particular, we establish its continuity with respect to the speed . In addition, for any continuous bounded non-negative initial data, we establish the long time behaviour of the solution . In the specific situation, and symmetric we also investigate the behaviour of the critical speeds and with respect to the tail of the kernel . We show in particular that even for very fat tailed kernel these two critical speeds exist.
中文翻译:
人口能否在使用非本地分散的不断变化的环境中生存?
在本文中,我们分析了非本地模型: 在哪里 是一个正的连续扩散核,并且 是描述人口增长率的异质 KPP 类型非线性。假设人口的生态位是有界的(即在一个紧凑集之外,假设环境对人口是致命的)并以恒定速度随时间移动. 对于紧凑支持的分散内核,假设对于 人口生存,我们证明存在临界速度 和 以至于对于所有人 那么人口将生存并在什么时候灭亡 或者 . 为了得出这些结果,我们首先根据速度获得最佳持久性标准对于具有漂移项的非局部问题。即,我们证明对于正速度 种群持续存在当且仅当广义主特征值 线性问题 是否定的。 是我们根据椭圆算子的广义第一特征值的精神定义的谱量。速度 和 然后通过对属性的精细分析获得 关于 . 特别地,我们建立了它在速度方面的连续性. 此外,对于任何连续有界非负初始数据,我们建立解决方案的长时间行为. 在特定情况下, 和 对称我们还研究了临界速度的行为 和 关于内核的尾部 . 我们特别表明,即使对于尾非常胖的内核,这两个临界速度也存在。