标题： 标量场势能的分类与宇宙学尺度解 显示英文标题

标题： A classification of scalar field potentials with cosmological scaling solutions

摘要： 获得当前宇宙学常数的一种有吸引力的方法是通过标量场的势能。 考虑包含完美流体和标量场的模型，我们对所有势能进行了分类，这些势能使得当完美流体密度占主导时，标量场的能量密度按尺度因子的幂律变化。 有三种可能性。 前两种是众所周知的；被广泛研究的指数势能使标量场模仿完美流体的演化，而对于由Ratra和Peebles引入的负幂律，标量场密度相对于流体密度增长。 第三种可能性是一种新的情况，其中势能是正幂律，而标量场能量密度相对于完美流体衰减。 我们提供了精确解及其稳定性特性的完整分析，并研究了各种可能的宇宙学应用。 显示英文摘要

摘要： An attractive method of obtaining an effective cosmological constant at the present epoch is through the potential energy of a scalar field. Considering models with a perfect fluid and a scalar field, we classify all potentials for which the scalar field energy density scales as a power-law of the scale factor when the perfect fluid density dominates. There are three possibilities. The first two are well known; the much-investigated exponential potentials have the scalar field mimicking the evolution of the perfect fluid, while for negative power-laws, introduced by Ratra and Peebles, the scalar field density grows relative to that of the fluid. The third possibility is a new one, where the potential is a positive power-law and the scalar field energy density decays relative to the perfect fluid. We provide a complete analysis of exact solutions and their stability properties, and investigate a range of possible cosmological applications.