How dark matter reionized the Universe
How dark matter reionized the Universe
复制标题
DOI：
10.1103/physrevd.80.035007
复制
发表时间：
2009-04
影响因子：
5
通讯作者：
A. Belikov;D. Hooper
中科院分区：
文献类型：
--
作者：
A. Belikov;D. Hooper
虽然经验证据表明宇宙的气体已经被红移z{approx_equal}6电离，但这种转变发生的机制仍然不清楚。在这篇文章中，我们探讨了暗物质湮灭可能在这一过程中发挥了主导作用的可能性。在这些湮灭中产生的高能电子可以与宇宙微波背景散射，产生相对低能量的伽马射线，其比更高能量的瞬发光子更有效地吸收和加热气体。与以前的研究相比，我们发现，具有电弱尺度质量的可行暗物质候选者可以自然地对宇宙的再电离做出主要贡献。有趣的是，我们发现暗物质候选者能够产生PAMELA观察到的最近的宇宙射线正电子过剩（或费米伽马射线太空望远镜测量的电子光谱），也被预测会导致宇宙的完全再电离z{approx}6。
Although empirical evidence indicates that the Universe's gas had become ionized by redshift z{approx_equal}6, the mechanism by which this transition occurred remains unclear. In this article, we explore the possibility that dark matter annihilations may have played the dominant role in this process. Energetic electrons produced in these annihilations can scatter with the cosmic microwave background to generate relatively low energy gamma rays, which ionize and heat gas far more efficiently than higher energy prompt photons. In contrast to previous studies, we find that viable dark matter candidates with electroweak scale masses can naturally provide the dominant contribution to the reionization of the Universe. Intriguingly, we find that dark matter candidates capable of producing the recent cosmic ray positron excesses observed by PAMELA (or the electrons spectrum measured by the Fermi Gamma Ray Space Telescope) are also predicted to lead to the full reionization of the Universe by z{approx}6.