论文标题
通货膨胀期间的粒子产生：从电离时期从红移的21 cm观测值中预期的限制
Particle production during inflation: constraints expected from redshifted 21 cm observations from the epoch of reionization
论文作者
论文摘要
我们检查了原始标量功率谱中的一种特征，即，由于膨胀过程中粒子产生的爆发而产生的类似颠簸的特征。 Planck 2018的最新CMB观察可以适应此类功能。在不久的将来，从电离时期对红移21 cm信号的观察可以通过在广泛的共同移动波数上利用预期的层析成像信息来对通货膨胀模型产生其他限制。在这项工作中，我们研究了即将到来的观察数据从SKA-LOW的潜力，以限制具有类似颠簸的特征的原始功率谱的参数。我们使用SKA-LOW预期的模拟模拟数据，并从不同的前景删除模型中估算出不确定性，并约束贝叶斯框架内原始特征的参数。我们研究了两种情况：在第一种情况下，已知与21 cm信号的演化相关的天体物理参数，我们发现21 cm功率谱确实有可能探测原始凸起的特征。由于凸起的输入幅度降低了原始功率谱的幅度的大约10％，而没有撞击，因此发现振幅的恢复值的不确定性和凸起的位置都会增加，并且凸起的位置恢复值也越来越偏向于更高的值。因此，限制这些参数变得越来越困难。在第二种情况下，我们分析了两个天体物理参数（即最小的光环质量和电离效率）时，对原始特征的可实现约束。我们发现，凸起对21 cm功率谱的形状和振幅的影响与改变天体物理参数的影响不同，因此可能会区分它们。
We examine a type of features in the primordial scalar power spectrum, namely, the bump-like feature(s) that arise as a result of burst(s) of particle production during inflation. The latest CMB observations by Planck 2018 can accommodate such features. In the near future, observations of redshifted 21 cm signal from the epoch of reionization can put additional constraints on inflation models by exploiting the expected tomographic information across a wide range of co-moving wave-numbers. In this work, we study the potential of upcoming observational data from SKA-Low to constrain the parameters of the primordial power spectrum with bump-like features. We use simulated mock data expected from SKA-Low, with uncertainties estimated from different foreground removal models, and constrain the parameters of primordial features within a Bayesian framework. We study two scenarios: in the first scenario, where the astrophysical parameters relevant to the evolution of the 21 cm signal are known, we find that 21 cm power spectra do have the potential to probe the primordial bump-like features. As the input amplitude of the bump is decreased below roughly 10% of the amplitude of the primordial power spectrum without the bump, the uncertainties in the recovered values for both amplitude and location of the bump are found to increase, and the recovered values of the location of the bump also get increasingly more biased towards higher values. Hence, it becomes harder to constrain these parameters. In the second scenario, we analyze the achievable constraints on primordial features when two of the astrophysical parameters, namely, minimum halo mass and ionizing efficiency are uncertain. We find that the effect of the bump on the shape and the amplitude of the 21 cm power spectrum is distinct from the impact of varying the astrophysical parameters, and hence they may potentially be distinguished.
