标题： 暗物质晕属性的统计力学解释 显示英文标题

标题： A statistical-mechanical explanation of dark matter halo properties

摘要： 宇宙N体模拟揭示了许多暗物质晕的经验关系，但这些晕属性的物理起源仍然不清楚。 另一方面，建立自引力系统统计力学的尝试遇到了许多形式上的困难，大约五十年来几乎没有取得进展。 本工作的目的是加强我们之前提出的统计力学方法解释暗物质晕属性的有效性。 通过引入有效压力代替径向压力来构建特定熵，我们使用熵原理，并以类似之前的方式得到一个熵平稳方程。 从这个熵平稳方程中推导出平衡暗晕的状态方程，通过该方程可以获得具有有限质量的暗晕密度剖面。 我们还推导了各向异性参数和伪相空间密度剖面。 所有这些预测在暗晕的外区与数值模拟结果高度一致。 我们的工作进一步支持了自引力系统统计力学是一个可行研究工具的观点。 显示英文摘要

摘要： Cosmological N-body simulations have revealed many empirical relationships of dark matter halos, yet the physical origin of these halo properties still remains unclear. On the other hand, the attempts to establish the statistical mechanics for self-gravitating systems have encountered many formal difficulties, and little progress has been made for about fifty years. The aim of this work is to strengthen the validity of the statistical-mechanical approach we have proposed previously to explain the dark matter halo properties. By introducing an effective pressure instead of the radial pressure to construct the specific entropy, we use the entropy principle and proceed in a similar way as previously to obtain an entropy stationary equation. An equation of state for equilibrated dark halos is derived from this entropy stationary equation, by which the dark halo density profiles with finite mass can be obtained. We also derive the anisotropy parameter and pseudo-phase-space density profile. All these predictions agree well with numerical simulations in the outer regions of dark halos. Our work provides further support to the idea that statistical mechanics for self-gravitating systems is a viable tool for investigation.