Evaluating Lyman- α constraints for general dark-matter velocity distributions: Multiple scales and cautionary tales
Evaluating Lyman- α constraints for general dark-matter velocity distributions: Multiple scales and cautionary tales
复制标题
评估一般暗物质速度分布的莱曼-α约束：多尺度和警示故事
DOI：
10.1103/physrevd.106.123521
复制
发表时间：
2022
影响因子：
5
通讯作者：
Yu, Hai-Bo
中科院分区：
文献类型：
--
作者：
Dienes, Keith R.;Huang, Fei;Kost, Jeff;Thomas, Brooks;Yu, Hai-Bo
对暗物质物理学可能模型的最重要的观测约束之一是利用与穿越星系际介质的光子相关的莱曼吸收光谱。由于这些数据使我们能够以很高的精度探测线性物质功率谱，直到相对较小的距离尺度，因此找到准确评估暗物质物理学大类候选模型的莱曼约束的方法是至关重要的。虽然这样的莱曼约束已被评估暗物质模型，产生相对简单的暗物质速度分布，更复杂的模型，特别是那些暗物质速度分布跨越多个尺度伸展最近受到越来越多的关注。在本文中，我们进行了研究的莱曼约束与一般暗物质的速度分布。虽然这样的莱曼约束在原则上很难评估，但在实践中，目前存在两类方法，通过这些方法，这些约束可以被改写成更容易评估的形式，从而可以更快地确定给定的暗物质模型是否被排除在外。因此，我们利用这两个重铸，以确定不同类别的暗物质速度分布的莱曼界限。我们还开发了一个通用的方法，这些不同的重铸的结果可以进行比较。对于相对简单的暗物质速度分布，我们证明了这两类重铸往往对齐，并给出类似的结果。然而，我们发现，涉及多个速度尺度的分布的情况要复杂得多：虽然这两类重铸继续在参数空间的某些区域内产生类似的结果，但它们在那些可能与现象学相关的参数空间区域内产生截然不同的结果。因此，这可以作为一个关于使用这种重铸复杂的暗物质速度分布的警示故事。
One of the most important observational constraints on possible models of dark-matter physics exploits the Lyman-absorption spectrum associated with photons traversing the intergalactic medium. Because these data allow us to probe the linear matter power spectrum with great accuracy down to relatively small distance scales, finding ways of accurately evaluating such Lyman-constraints across large classes of candidate models of dark-matter physics is of paramount importance. While such Lyman-constraints have been evaluated for dark-matter models that give rise to relatively simple dark-matter velocity distributions, more complex models—particularly those whose dark-matter velocity distributions stretch across multiple scales—have recently been receiving increasing attention. In this paper, we undertake a study of the Lyman-constraints associated with general dark-matter velocity distributions. Although such Lyman-constraints are difficult to evaluate in principle, in practice there currently exist two classes of methods in the literature through which such constraints can be recast into forms which are easier to evaluate and which therefore allow a more rapid determination of whether a given dark-matter model is ruled in or out. Accordingly, we utilize both of these recasts in order to determine the Lyman-bounds on different classes of dark-matter velocity distributions. We also develop a general method by which the results of these different recasts can be compared. For relatively simple dark-matter velocity distributions, we demonstrate that these two classes of recasts tend to align and give similar results. However, we find that the situation is far more complex for distributions involving multiple velocity scales: while these two classes of recasts continue to yield similar results within certain regions of parameter space, they nevertheless yield dramatically different results within precisely those regions of parameter space which are likely to be phenomenologically relevant. This, then, serves as a cautionary tale regarding the use of such recasts for complex dark-matter velocity distributions.