Long-lived light mediator to dark matter and primordial small scale spectrum
Long-lived light mediator to dark matter and primordial small scale spectrum
复制标题
暗物质和原始小尺度光谱的长寿命光介体
DOI：
10.1088/1475-7516/2015/05/008
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发表时间：
2015
影响因子：
6.4
通讯作者：
Yue Zhang
中科院分区：
文献类型：
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作者：
Yue Zhang
我们计算的背景下，简单的暗扇区模型包含一个GeV尺度的光介质的暗物质能量密度的扰动的早期宇宙演化。我们考虑的情况下，调解人是长寿的，寿命长达一秒，并在衰变之前，它暂时主导宇宙的能量密度。我们表明，原始扰动进入视界在此期间，线性增长的物质支配和碰撞阻尼之间的相互作用，一般可以导致暗物质密度扰动的频谱中的一个尖锐的峰值。结果，最小DM晕的群体得到增强。这种情况下可能产生的影响进行了讨论。
We calculate the early universe evolution of perturbations in the dark matter energy density in the context of simple dark sector models containing a GeV scale light mediator. We consider the case that the mediator is long-lived, with lifetime up to a second, and before decaying it temporarily dominates the energy density of the universe. We show that for primordial perturbations that enter the horizon around this period, the interplay between linear growth during matter domination and collisional damping can generically lead to a sharp peak in the spectrum of dark matter density perturbation. As a result, the population of the smallest DM halos gets enhanced. Possible implications of this scenario are discussed.