Nonlinear structure formation in Bound Dark Energy
Nonlinear structure formation in Bound Dark Energy
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DOI：
10.1088/1475-7516/2020/03/016
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发表时间：
2019-07
影响因子：
6.4
通讯作者：
E. Almaraz;Baojiu Li;A. Macorra
中科院分区：
文献类型：
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作者：
E. Almaraz;Baojiu Li;A. Macorra
研究了束缚暗能量模型（BDE）中非线性结构的形成，其中暗能量对应于在凝聚能标Λc下动态形成的轻标量介子粒子.这个暗能量介子的演化由势V（λ）=Λc4+2/3 <$−2/3决定，其现象学与其他的精粹方案不同。特别是，宇宙的膨胀率不仅在后期受到影响，而且在Λ CDM凝聚发生时也会受到影响，这在线性理论中导致小尺度上物质扰动的增强（相对于标准ΛCDM）。我们研究了有多少这个签名仍然存在，在晚些时候，以及通过N体模拟的非线性制度中的暗物质晕的属性。我们的研究结果表明，非线性校正洗了这个功能，从物质的功率谱，甚至在DE成为主导。然而，由于DE的独特晚期动力学，在最大尺度上，今天的BDE光谱有2%的小但明显的抑制。BDE和ΛCDM在成团能力上的差异反映在晕质量函数中，在BDE中小晕比大的重结构更丰富，因为宇宙的膨胀历史延迟了它们的形成。这一结果可以用半解析的Sheth-Tormen公式很好地描述。然而，尽管有这些差异，晕浓度参数在两个模型中基本相同，这表明一旦晕形成，晕内的聚类与一般膨胀解耦。
We study nonlinear structure formation in the Bound Dark Energy model (BDE), where dark energy (DE) corresponds to a light scalar meson particle ϕ dynamically formed at a condensation energy scale Λc. The evolution of this dark-energy meson is determined by the potential V(ϕ)=Λc4+2/3ϕ−2/3, with a distinguishing phenomenology from other quintessence scenarios. Particularly, the expansion rate of the universe is affected not only at late times, but also when the condensation of ϕ occurs, which in linear theory leads to an enhancement (with respect to standard ΛCDM) of matter perturbations on small scales. We study how much of this signature is still present at late times as well as the properties of dark matter halos in the nonlinear regime through N-body simulations. Our results show that nonlinear corrections wash out this feature from the matter power spectrum even before DE becomes dominant. There is, however, a small but clear suppression of the BDE spectrum of 2% today on the largest scales due to the distinct late-time dynamics of DE. The differences on the clustering power between BDE and ΛCDM are reflected in the halo mass function, where small halos are more abundant in BDE as opposed to large heavy structures, whose formation is delayed because of the expansion history of the universe. This result is well captured by the semi-analytical Sheth-Tormen formula. However, despite these differences, the halo concentration parameter is essentially the same in both models, which suggest that clustering inside the halos decouple from the general expansion once the halos form.