标题： 暗物质玻色-爱因斯坦凝聚的宇宙动力学 显示英文标题

标题： Cosmological dynamics of dark matter Bose-Einstein Condensation

摘要： 一旦宇宙玻色子气体的临界温度低于临界温度，宇宙历史过程中总可以发生玻色-爱因斯坦凝聚过程。 在玻色-爱因斯坦凝聚模型中，暗物质可以被描述为一个非相对论性的、牛顿引力凝聚体，其密度和压力由状态方程以正则指数关联，且正则指数等于一。 在目前的研究中，我们通过假设这个过程可以被描述（至少近似）为一级相变来研究宇宙背景下的玻色-爱因斯坦凝聚过程。我们分析了早期宇宙物理描述相关的物理量（即能量密度、温度和标度因子）在玻色-爱因斯坦凝聚（相变）之前、期间和之后的演化。 我们也详细考虑了宇宙演化的时期，当宇宙通过混合凝聚态-正常暗物质阶段演化时，具有单调增长的玻色-爱因斯坦暗物质成分。 一个重要的参数表征玻色-爱因斯坦凝聚是凝聚暗物质分数，其时间演化描述了转换过程的时间动力学。 该参数在宇宙凝聚过程中的行为也进行了详细分析。 为了研究宇宙动力学和演化，我们使用了分析方法和数值方法。 凝聚暗物质的存在以及玻色-爱因斯坦相变可能极大地改变了早期宇宙的宇宙演化过程，以及大尺度结构形成过程。 显示英文摘要

摘要： Once the critical temperature of a cosmological boson gas is less than the critical temperature, a Bose-Einstein Condensation process can always take place during the cosmic history of the universe. In the Bose-Einstein Condensation model, dark matter can be described as a non-relativistic, Newtonian gravitational condensate, whose density and pressure are related by a barotropic equation of state, with barotropic index equal to one. In the present work, we study the Bose-Einstein Condensation process in a cosmological context, by assuming that this process can be described (at least approximately) as a first order phase transition. We analyze the evolution of the physical quantities relevant for the physical description of the early universe, namely, the energy density, temperature and scale factor, before, during and after the Bose-Einstein Condensation (phase transition). We also consider in detail the epoch when the universe evolved through a mixed condensate - normal dark matter phase, with a monotonically growing Bose-Einstein dark matter component. An important parameter characterizing the Bose-Einstein Condensation is the condensate dark matter fraction, whose time evolution describes the time dynamics of the conversion process. The behavior of this parameter during the cosmological condensation process is also analyzed in detail. To study the cosmological dynamics and evolution we use both analytical and numerical methods. The presence of the condensate dark matter and of the Bose-Einstein phase transition could have modified drastically the cosmological evolution of the early universe, as well as the large scale structure formation process.