论文标题
宇宙结构形成的动力学场理论
Kinetic Field Theory for Cosmic Structure Formation
论文作者
论文摘要
我们将动力场理论应用于非线性宇宙结构的形成。动力场理论将宇宙密度场分解为颗粒，并通过相空间遵循其轨迹。我们假设初始粒子矩是从高斯随机场中绘制的。我们特别强调了晚期，渐近行为，这是在构型和速度空间中粒子分布的低阶统计测量量的小空间尺度上。我们的主要结果是，沿Zel'Dovich轨迹自由流媒体的集合中的密度和速度波动的功率光谱渐近地散开，波浪数$ k $如$ k^{ - 3} $ for $ k \ for $ k \ for \ k \ fo \ fo \ infty $，无论是对宇宙学模型和deardements the deardements the deardements the the deardements n of the deardements n of the the the deardements abless of the the the deardements的数量。如果在平均场近似中考虑粒子相互作用，则该结论对于密度 - 透明功率谱仍然有效。我们还表明，在相同的一般条件下，自由流粒子的双光谱渐近地脱落。
We apply kinetic field theory to non-linear cosmic structure formation. Kinetic field theory decomposes the cosmic density field into particles and follows their trajectories through phase space. We assume that initial particle momenta are drawn from a Gaussian random field. We place particular emphasis on the late-time, asymptotic behaviour on small spatial scales of low-order statistical measures for the distribution of particles in configuration and velocity space. Our main result is that the power spectra for density and velocity fluctuations in ensembles of particles freely streaming along Zel'dovich trajectories asymptotically fall off with wave number $k$ like $k^{-3}$ for $k\to\infty$, irrespective of the cosmological model and the type of dark matter assumed, with the exponent set only by the number of spatial dimensions. This conclusion remains valid for density-fluctuation power spectra if particle interactions are taken into account in a mean-field approximation. We also show that the bispectrum of freely-streaming particles falls off asymptotically like $k^{-11/2}$ under the same general conditions.
