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arXiv 1012.0002astro-ph.COgr-qc
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阐明相互作用的暗能量对线性和非线性结构形成过程的影响

Clarifying the effects of interacting dark energy on linear and nonlinear structure formation processes

Marco Baldi

摘要:

我们提出了一个详细的数值研究的影响,宇宙模型具有直接相互作用的暗能量组件,驱动宇宙的加速膨胀和冷暗物质可以对结构形成的线性和非线性阶段。通过一系列无碰撞N体模拟,我们研究了这些宇宙学模型特征的每个不同效应的影响-其中包括第五种力,粒子质量的时间变化和速度依赖的加速度-分别对密度扰动的增长和一系列与线性和非线性宇宙结构相关的可观测量,作为物质功率谱、重子与冷暗物质之间的引力偏差、晕质量函数和晕密度分布。我们应用和比较文献中以前采用的不同数值方法进行分析,并解决Li & Barrow(2010 b)最近在一项类似研究中声称的与Baldi等人(2010)的第一个结果有关的部分差异。我们的研究结果充分证实了Baldi等人(2010)的结论,并表明当暗能量与冷暗物质相互作用的线性和非线性效应被适当地解开时,速度依赖加速度是作用于非线性尺度的主导效应,尤其是降低冷暗物质晕浓度的最重要机制。

英文摘要:

We present a detailed numerical study of the impact that cosmological models featuring a direct interaction between the Dark Energy component that drives the accelerated expansion of the Universe and Cold Dark Matter can have on the linear and nonlinear stages of structure formation. By means of a series of collisionless N-body simulations we study the influence that each of the different effects characterizing these cosmological models - which include among others a fifth force, a time variation of particle masses, and a velocity-dependent acceleration - separately have on the growth of density perturbations and on a series of observable quantities related to linear and nonlinear cosmic structures, as the matter power spectrum, the gravitational bias between baryons and Cold Dark Matter, the halo mass function and the halo density profiles. We perform our analysis applying and comparing different numerical approaches previously adopted in the literature, and we address the partial discrepancies recently claimed in a similar study by Li & Barrow (2010b) with respect to the first outcomes of Baldi et al. (2010), which are found to be related to the specific numerical approach adopted in the former work. Our results fully confirm the conclusions of Baldi et al. (2010) and show that when linear and nonlinear effects of the interaction between Dark Energy and Cold Dark Matter are properly disentangled, the velocity-dependent acceleration is the leading effect acting at nonlinear scales, and in particular is the most important mechanism in lowering the concentration of Cold Dark Matter halos.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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