Scalar and vector perturbations in a universe with discrete and continuous matter sources
Scalar and vector perturbations in a universe with discrete and continuous matter sources
复制标题
具有离散和连续物质源的宇宙中的标量和矢量扰动
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
A. Zhuk
中科院分区：
文献类型：
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作者：
M. Eingorn;C. Kiefer;A. Zhuk
我们研究一个充满离散不均匀形式的尘埃状物质的宇宙（例如，星系及其集团和集群）和两套完美流体的线性和非线性状态方程。背景时空几何由FLRW度规定义。在弱引力场极限下，我们发展了一阶标量和矢量宇宙学微扰理论。我们的方法适用于所有的宇宙尺度（即亚视界和超视界的），并结合了线性和非线性效应的能量密度波动。我们证明了标量扰动（即引力势）以及矢量扰动可以被分解为来自每个物质源的单独贡献。每一种贡献都满足自己的方程。速度无关的部分的个人引力势的特点是由一个有限的时间依赖汤川相互作用范围是相同的每个单独的贡献。我们还得到了与离散物质源有关的引力势和矢量微扰的精确形式。我们的方法的自洽性被彻底检查。导出的方程可以形成广泛的一类宇宙学模型的数值模拟的理论基础。
We study a universe filled with dust-like matter in the form of discrete inhomogeneities (e.g., galaxies and their groups and clusters) and two sets of perfect fluids with linear and nonlinear equations of state, respectively. The background spacetime geometry is defined by the FLRW metric. In the weak gravitational field limit, we develop the first-order scalar and vector cosmological perturbation theory. Our approach works at all cosmological scales (i.e. sub-horizon and super-horizon ones) and incorporates linear and nonlinear effects with respect to energy density fluctuations. We demonstrate that the scalar perturbation (i.e. the gravitational potential) as well as the vector perturbation can be split into individual contributions from each matter source. Each of these contributions satisfies its own equation. The velocity-independent parts of the individual gravitational potentials are characterized by a finite time-dependent Yukawa interaction range being the same for each individual contribution. We also obtain the exact form of the gravitational potential and vector perturbation related to the discrete matter sources. The self-consistency of our approach is thoroughly checked. The derived equations can form the theoretical basis for numerical simulations for a wide class of cosmological models.