标题： 非厄米 formalism 和非线性物理 显示英文标题

标题： Non-Hermitian formalism and nonlinear physics

摘要： 目前，非厄米理论被许多论文用于描述开放量子系统。 这个物理领域发展出了一种特殊的语言，使得许多物理学家难以跟随和理解相应的论文。 我们表明，非厄米理论的特征特性只不过是当哈密顿量为非厄米时可能出现在方程中的非线性项。 它们直接与奇异点（通常称为例外点，EPs）相关。 在低能级密度下，它们可能导致反直觉的物理结果，使我们能够解释一些令人困惑的实验结果。 在高能级密度下，它们决定了系统的动力学。 显示英文摘要

摘要： The non-Hermitian formalism is used at present in many papers for the description of open quantum systems. A special language developed in this field of physics which makes it difficult for many physicists to follow and to understand the corresponding papers. We show that the characteristic features of the non-Hermitian formalism are nothing but nonlinearities that may appear in the equations when the Hamiltonian is non-Hermitian. They are related directly to singular points (called mostly exceptional points, EPs). At low level density, they may cause counterintuitive physical results which allow us to explain some puzzling experimental results. At high level density, they determine the dynamics of the system.