论文标题
无碰撞等离子体中最大熵的非热粒子加速度
Nonthermal particle acceleration from maximum entropy in collisionless plasmas
论文作者
论文摘要
耗散过程会导致许多系统中无碰撞等离子体，以开发具有广泛幂律的非热粒子分布。在空间/天体物理观测中的幂律能量分布的流行率和具有多种加速度和诱捕（或逃逸）机制的系统的动力学模拟引起了深层的谜团。我们认为，当考虑到Boltzmann-Gibbs熵之外的概括时，可以根据最大渗透原理对此类分布进行建模的可能性。使用熵的尺寸表示（与Renyi和Tsallis熵有关），我们通过由不可逆的耗散发生的特征能量尺度确定的幂律尾巴来得出广义的最大透镜分布。通过假设颗粒通常在平衡之前通过与自由能（每个粒子）相当的量进行通电，我们会在具有足够复杂拓扑的系统中得出幂律指数的公式，这是血浆参数的函数。该模型重现了相对论湍流和磁重新连接的动力学模拟的几个结果。
Dissipative processes cause collisionless plasmas in many systems to develop nonthermal particle distributions with broad power-law tails. The prevalence of power-law energy distributions in space/astrophysical observations and kinetic simulations of systems with a variety of acceleration and trapping (or escape) mechanisms poses a deep mystery. We consider the possibility that such distributions can be modeled from maximum-entropy principles, when accounting for generalizations beyond the Boltzmann-Gibbs entropy. Using a dimensional representation of entropy (related to the Renyi and Tsallis entropies), we derive generalized maximum-entropy distributions with a power-law tail determined by the characteristic energy scale at which irreversible dissipation occurs. By assuming that particles are typically energized by an amount comparable to the free energy (per particle) before equilibrating, we derive a formula for the power-law index as a function of plasma parameters for magnetic dissipation in systems with sufficiently complex topologies. The model reproduces several results from kinetic simulations of relativistic turbulence and magnetic reconnection.
