Understanding the suppression of structure formation from dark matter-dark energy momentum coupling
Understanding the suppression of structure formation from dark matter-dark energy momentum coupling
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DOI：
10.1103/physrevd.101.043531
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发表时间：
2019-12
影响因子：
5
通讯作者：
Finlay Noble Chamings;A. Avgoustidis;E. Copeland;A. Green;A. Pourtsidou
中科院分区：
文献类型：
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作者：
Finlay Noble Chamings;A. Avgoustidis;E. Copeland;A. Green;A. Pourtsidou
标量场暗能量通过纯动量耦合与暗物质相互作用的模型先前已经被发现可能缓解早期和晚期宇宙观测之间的结构形成张力。在这篇文章中，我们将探讨这一特征背后的物理机制。我们分析地认为扰动增长方程意味着结构增长的抑制，并用数值计算来说明我们的讨论。然后，我们将先前研究的暗能量和暗物质之间的二次耦合推广到更一般的幂律情况下，也允许暗能量指数势的斜率变化。我们发现，结构生长抑制是幂律耦合的一个通用功能，它可以在一个参数值的范围内，比以前发现的要大。
Models in which scalar field dark energy interacts with dark matter via a pure momentum coupling have previously been found to potentially ease the structure formation tension between early- and late-universe observations. In this article we explore the physical mechanism underlying this feature. We argue analytically that the perturbation growth equations imply the suppression of structure growth, illustrating our discussion with numerical calculations. Then we generalise the previously studied quadratic coupling between the dark energy and dark matter to a more general power law case, also allowing for the slope of the dark energy exponential potential to vary. We find that the structure growth suppression is a generic feature of power law couplings and it can, for a range of parameter values, be larger than previously found.