等离子体非线性手性:有螺统计及可积结构

Plasma nonlinear chirality:Helical statistics and integrable structures

在等离子体湍流,如太阳风中产生的螺旋现象和谐振现象具有典型的非线性行为特征.等离子湍流在不同条件下可以有不同的动力学特征,容许存在各种非线性结构.本文主要讨论了等离子湍流中由单手性主导的湍动涡模态和(近)可积结构(如呼吸子):前者可以通过扩展磁流体统计模型的某种统计解来说明;而对于等离子湍流中是否存在可积结构,本文通过对水波、等离子体和玻色-爱因斯坦凝聚的类比分析来加以推断.本文以呼吸子可能有贡献为例说明,将采样频谱中有限频率部分视为线性波的分析不一定准确.

In plasma turbulence, the helical and(nearly) periodic phenomena do not necessarily correspond to linear waves. Plasmas in different environments present distinct dynamical characters, including various nonlinear structures, and two alternative nonlinear mechanisms are presented to be able to lead to relevant sub-ion chirality issues in solar winds: helical turbulent modes and integrable structures(e.g., the breathers). The former is explained by revisiting a recent proposal on studying solar wind with extended magnetohydrodynamics;the latter is argued with multidisciplinary-supporting information. If there are possible contributions from breathers, it may not be accurate to attribute the non-zero frequency spectrum to the propagating(linear) waves.