论文标题
无碰撞轨道的统计力学。 V.理想化的自我磨削系统的平衡方法
Statistical Mechanics of Collisionless Orbits. V. The approach to equilibrium for idealized self-gravitating systems
论文作者
论文摘要
由大量粒子组成的自我磨碎的牛顿系统通常没有尝试使用统计力学来描述它们。这是自相矛盾的，因为许多天文学系统或其模拟似乎都具有不存在物理基础的通用平衡结构。十年前，我们表明，在保守的总能量和质量的限制下，用给定能量给定能量的微骨数量极端，导致最大熵状态，$ n（e）\ propto \ exp \ exp（-β（e-Φ_0）） - 1 $，称为darkexp。这种差异能量分布以及所得的密度结构，与中央尖端，$ρ\ sim r^{ - 1} $和外部零件紧密近似深色晕孔的结构，$ρ\ sim r^{ - 4} $。在这里，我们定义了一个非平衡功能，$ s_d $，该功能最大化Darkexp，并在进化过程中单调增加，朝向扩展的球形信息模型的理想化无碰撞系统的平衡。更接近darkexp的混合的系统。
Self-gravitating Newtonian systems consisting of a very large number of particles have generally defied attempts to describe them using statistical mechanics. This is paradoxical since many astronomical systems, or simulations thereof, appear to have universal, equilibrium structures for which no physical basis exist. A decade ago we showed that extremizing the number of microstates with a given energy per unit mass, under the constraints of conserved total energy and mass, leads to the maximum entropy state, $n(E) \propto \exp (-β(E-Φ_0))-1$, known as DARKexp. This differential energy distribution, and the resulting density structures, closely approximate those of dark-matter halos with central cusps, $ρ\sim r^{-1}$, and outer parts, $ρ\sim r^{-4}$. Here we define a non-equilibrium functional, $S_D$, which is maximized for DARKexp and increases monotonically during the evolution towards equilibrium of idealized collisionless systems of the Extended Spherical Infall Model. Systems that undergo more mixing more closely approach DARKexp.
