A field theory approach to the evolution of canonical helicity and energy
A field theory approach to the evolution of canonical helicity and energy
复制标题
正则螺旋度和能量演化的场论方法
DOI：
10.1063/1.4956465
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
S. You
中科院分区：
文献类型：
--
作者：
S. You
重新定义了场中多粒子系统的拉格朗日量，将控制流体和等离子体动力学的单粒子、动力学和流体方程重新表述为一组广义麦克斯韦方程和正则力场的欧姆定律。拉格朗日包括了新的术语，表示粒子分布的运动、分布和电磁场之间的耦合，以及相对论贡献。该公式表明，自组织和正则螺旋度输运的概念适用于经典和相对论尺度上的单粒子、动力学和流体区域。该理论为比较一般系统的正则螺旋度变化和能量变化提供了基础。例如，在一个受到非保守力作用的固定的孤立系统中，只有当密度或分布函数的梯度很浅时，物种的正则螺旋度才比总能量变化小。
A redefinition of the Lagrangian of a multi-particle system in fields reformulates the single-particle, kinetic, and fluid equations governing fluid and plasma dynamics as a single set of generalized Maxwell's equations and Ohm's law for canonical force-fields. The Lagrangian includes new terms representing the coupling between the motion of particle distributions, between distributions and electromagnetic fields, with relativistic contributions. The formulation shows that the concepts of self-organization and canonical helicity transport are applicable across single-particle, kinetic, and fluid regimes, at classical and relativistic scales. The theory gives the basis for comparing canonical helicity change to energy change in general systems. For example, in a fixed, isolated system subject to non-conservative forces, a species' canonical helicity changes less than total energy only if gradients in density or distribution function are shallow.