The 21cm line probes the evolution of matter perturbations over a wide range of redshifts, from the dark ages down to the completion of reionization. Observing the 21cm cosmological signal will extend our understanding of the evolution of the Universe and it is thus important to investigate the predictions of different cosmological models. In this paper we focus on the prospect of constraining coupled quintessence models during the Epoch of Reionization both for global signal experiments and for intensity mapping surveys. To derive the all-sky 21cm signal and fluctuations in coupled quintessence, we simulate cosmological volumes of the 21cm signal including the coupling between dark matter and the quintessence field, where the strength of the coupling is labeled by the parameter $Q$. We show that the coupling between dark matter and quintessence modifies structure formation and expedites the process of reionization. For the upcoming 21cm line surveys like SKA and a fiducial global 21cm signal experiment, we perform a Fisher matrix analysis to constrain the coupling $Q$ and the dark matter density parameter $\Omega_\mathrm{dm}$. The results indicate that SKA will be able to place a 68% upper limit $0.04$ to $|Q|$. At the same time, such a global 21cm detector provides a constraint on the dark matter density parameter $\Omega_\mathrm{dm}$ around $\Delta\Omega_{\rm dm}\approx 0.005$, whereas SKA sets a quite weaker constraint around $\Delta\Omega_{\rm dm}\approx0.1$. These constraints are comparable to those already obtained from the cosmic microwave background, but explore an entirely different redshift range.

中文翻译：

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用 21 cm 信号约束耦合精髓

21 厘米长的线探测了从黑暗时代到再电离完成的广泛红移范围内物质扰动的演变。观察 21 厘米宇宙学信号将扩展我们对宇宙演化的理解，因此研究不同宇宙学模型的预测非常重要。在本文中，我们重点关注在再电离时代约束耦合精髓模型的前景，用于全球信号实验和强度映射调查。为了推导出全天空 21cm 信号和耦合精华的波动，我们模拟了 21cm 信号的宇宙学体积，包括暗物质和精华场之间的耦合，其中耦合强度由参数 $Q$ 标记。我们表明，暗物质和精华之间的耦合改变了结构形成并加速了再电离过程。对于即将到来的 21cm 线勘测，如 SKA 和基准全球 21cm 信号实验，我们执行 Fisher 矩阵分析以约束耦合 $Q$ 和暗物质密度参数 $\Omega_\mathrm{dm}$。结果表明，SKA 将能够将 $0.04$ 的 68% 上限设置为 $|Q|$。同时，这样的全局 21cm 探测器对暗物质密度参数 $\Omega_\mathrm{dm}$ 提供了约 $\Delta\Omega_{\rm dm}\approx 0.005$ 的约束，而 SKA 设置了一个相当弱的$\Delta\Omega_{\rm dm}\approx0.1$ 周围的约束。这些限制与已经从宇宙微波背景中获得的限制相当，但探索的是一个完全不同的红移范围。