标题： 仿射引力的宇宙学动力学 显示英文标题

标题： Cosmological dynamics of mimetic gravity

摘要： 我们对模仿引力中模仿标量场的一般势能的动力学行为进行了详细研究。通过相空间和稳定性分析，我们表明该场景可以成功描述宇宙的热历史，即辐射、物质和暗能量时代的连续序列。此外，在晚期，宇宙可以接近德西特解，或者接近一种标度加速吸引子，在这种情况下，暗物质和暗能量密度参数处于同一数量级，从而缓解了宇宙巧合问题。将我们的通用分析应用于各种特定势能选择，包括幂律和指数势能，我们表明模仿引力可以与宇宙的观测行为良好一致。此外，通过一个倒平方势能，我们发现模仿引力提供了一个引人注目的统一宇宙学场景，其中暗能量和暗物质均由单一标量场表征，并且宇宙巧合问题得到缓解。 显示英文摘要

摘要： We present a detailed investigation of the dynamical behavior of mimetic gravity with a general potential for the mimetic scalar field. Performing a phase-space and stability analysis, we show that the scenario at hand can successfully describe the thermal history of the universe, namely the successive sequence of radiation, matter, and dark-energy eras. Additionally, at late times the universe can either approach a de Sitter solution, or a scaling accelerated attractor where the dark-matter and dark-energy density parameters are of the same order, thus offering an alleviation of the cosmic coincidence problem. Applying our general analysis to various specific potential choices, including the power-law and the exponential ones, we show that mimetic gravity can be brought into good agreement with the observed behavior of the universe. Moreover, with an inverse square potential we find that mimetic gravity offers an appealing unified cosmological scenario where both dark energy and dark matter are characterized by a single scalar field, and where the cosmic coincidence problem is alleviated.