Femtolensing by dark matter revisited
Femtolensing by dark matter revisited
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DOI：
10.1088/1475-7516/2018/12/005
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发表时间：
2018-07
影响因子：
6.4
通讯作者：
A. Katz;J. Kopp;S. Sibiryakov;W. Xue
中科院分区：
文献类型：
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作者：
A. Katz;J. Kopp;S. Sibiryakov;W. Xue
伽玛射线暴（GRB）的飞秒透镜效应被认为是探测质量低于10−13太阳质量的奇异天体的一种令人兴奋的可能性，例如小型原始黑洞或超致密暗物质微晕，例如由QCD轴子组成。在本文中，我们批判性地审查这一想法，适当地考虑到扩展的性质的来源以及波动光学效应。我们证明，大多数伽玛暴是不合适的femtolensing搜索，由于其大尺寸。这消除了之前原始黑洞的毫微微透镜界限，这意味着原始黑洞暗物质的参数空间的广大区域没有受到鲁棒约束。尽管如此，我们仍然认为有一小部分以快速变化为特征的伽玛暴可能具有较小的尺寸并且是有用的。然而，需要观察大量的这种突发以实现有意义的约束。我们研究了未来观测的灵敏度作为检测到的伽玛暴的数量和发射区域的大小的函数。
Femtolensing of gamma ray bursts (GRBs) has been put forward as an exciting possibility to probe exotic astrophysical objects with masses below 10−13 solar masses such as small primordial black holes or ultra-compact dark matter minihalos, made up for instance of QCD axions. In this paper we critically review this idea, properly taking into account the extended nature of the source as well as wave optics effects. We demonstrate that most GRBs are inappropriate for femtolensing searches due to their large sizes. This removes the previous femtolensing bounds on primordial black holes, implying that vast regions of parameter space for primordial black hole dark matter are not robustly constrained. Still, we entertain the possibility that a small fraction of GRBs, characterized by fast variability can have smaller sizes and be useful. However, a large number of such bursts would need to be observed to achieve meaningful constraints. We study the sensitivity of future observations as a function of the number of detected GRBs and of the size of the emission region.