Extracting dark-matter velocities from halo masses: A reconstruction conjecture
Extracting dark-matter velocities from halo masses: A reconstruction conjecture
复制标题
DOI：
10.1103/physrevd.106.083506
复制
发表时间：
2021-01
影响因子：
5
通讯作者：
K. Dienes;F. Huang;Jeff Kost;K. Manogue;B. Thomas
中科院分区：
文献类型：
--
作者：
K. Dienes;F. Huang;Jeff Kost;K. Manogue;B. Thomas
最近越来越多的注意力集中在非传统的暗物质生产机制，导致原始的暗物质的速度分布与高度非热的形状。在本文中，我们进行了评估如何详细的形状一般暗物质的速度分布影响结构形成的非线性制度。特别是，我们调查的晕质量和次晕质量函数的影响，以及对天体物理观测，如卫星和集群数量计数。我们发现，许多标准的期望不再持有的情况下，这种速度分布采取高度非平凡的，甚至多模态的形状。例如，我们发现，单独的名义自由流尺度不足以表征自由流对结构形成的影响。此外，我们提出了一个简单的单线猜想，它可以用来“重建”的原始暗物质的速度分布直接从晕质量函数的形状。虽然我们的猜想是完全启发式的，我们表明，它成功地再现了显着的特点，即使是非平凡的分布，这是高度非热和/或多模态，如可能发生的非最小的暗扇区的底层暗物质的速度分布。此外，由于我们的方法只依赖于晕质量函数，我们的猜想提供了一种探测暗物质性质的方法，即使是在暗物质和可见物质只在引力作用下相互作用的情况下。
Increasing attention has recently focused on non-traditional dark-matter production mechanisms which result in primordial dark-matter velocity distributions with highly non-thermal shapes. In this paper, we undertake an assessment of how the detailed shape of a general dark-matter velocity distribution impacts structure formation in the non-linear regime. In particular, we investigate the impact on the halo-mass and subhalo-mass functions, as well as on astrophysical observables such as satellite and cluster-number counts. We find that many of the standard expectations no longer hold in situations in which this velocity distribution takes a highly non-trivial, even multi-modal shape. For example, we find that the nominal free-streaming scale alone becomes insufficient to characterize the effect of free-streaming on structure formation. In addition, we propose a simple one-line conjecture which can be used to “reconstruct” the primordial dark-matter velocity distribution directly from the shape of the halo-mass function. Although our conjecture is completely heuristic, we show that it successfully reproduces the salient features of the underlying dark-matter velocity distribution even for non-trivial distributions which are highly non-thermal and/or multi-modal, such as might occur for non-minimal dark sectors. Moreover, since our approach relies only on the halo-mass function, our conjecture provides a method of probing dark-matter properties even for scenarios in which the dark and visible sectors interact only gravitationally.