Giant amplification of small perturbations in frictional amorphous solids.
Giant amplification of small perturbations in frictional amorphous solids.
复制标题
摩擦非晶固体中小扰动的巨大放大。
DOI：
--
复制
发表时间：
2020
影响因子：
2.4
通讯作者：
Yarden Sheffer
中科院分区：
文献类型：
--
作者：
Harish Charan;O. Gendelman;I. Procaccia;Yarden Sheffer
自然界中的灾难性事件常常是由微小的扰动引发的，地震的“远程触发”就是一个重要的例子。在这里，我们提出了一种小扰动巨大放大的机制，预计该机制在动力学无法从哈密顿量导出的系统中是通用的。我们对所涉及的典型不稳定性（随着噪声呈指数增加而振荡）进行一般讨论，并详细检查确定相关动态的正常形式。对于有或没有耗散的系统，解释了对外部扰动的高敏感性。使用摩擦颗粒物质的动力学提供了数值示例。最后，我们指出当前讨论的现象与非厄米哈密顿量量子模型中高度热门的“例外点”问题之间的关系。
Catastrophic events in nature can be often triggered by small perturbations, with "remote triggering" of earthquakes being an important example. Here we present a mechanism for the giant amplification of small perturbations that is expected to be generic in systems whose dynamics is not derivable from a Hamiltonian. We offer a general discussion of the typical instabilities involved (being oscillatory with an exponential increase of noise) and examine in detail the normal forms that determine the relevant dynamics. The high sensitivity to external perturbations is explained for systems with and without dissipation. Numerical examples are provided using the dynamics of frictional granular matter. Finally, we point out the relationship of the presently discussed phenomenon to the highly topical issue of "exceptional points" in quantum models with non-Hermitian Hamiltonians.