标题：PRIMORDIAL BLACK HOLES AS DARK MATTER Bernard

• focus on 暴胀产生的PBH
• 由于LIGO的观测，中等太阳质量（1~10^3个太阳质量）PBH是暗物质的可能性备受关注；普朗克尺度的PBH也很有趣但是不可检验

INTRODUCTION

• PBH还未证实
• "The fact that Hawking was only led to this discovery through contemplating the properties of PBHs illustrates that it can be useful to study something even if it may not exist!"
• 质量小于10^15g的PBH已经蒸发（受霍金辐射影响显著） → 对早期宇宙的模型给出限制
• 蒸发的PBH的特征：①系外与星系伽马射线背景；②宇宙射线中的反物质（※）；③星系中心的annihilation line radiation（湮灭线辐射？）
• 现存的PBH的作用：①星系核supermassive black hole的“种子”；②通过poisson fluctuations产生标量结构；③影响宇宙的热力学和再电离历史
• 暗物质候选者很少，除PBH外还有Weakly Interacting Massive Particle(WIMP,弱相互作用质量粒子)，例如最轻的超对称粒子或者轴子

• 对各个间接观测或理论给出的PBH质量范围进行讨论

  About a decade ago, these lensing and dynamical constraints appeared to allow three mass ranges in which PBHs
  could provide the dark matter [34]: the subatomic-size range (1016 – 1017 g), the sublunar mass range (1020 – 1026 g) and what is sometimes termed the intermediate-mass black hole (IMBH) range (10 – 105 M).1 The lowest range may now be excluded by Galactic γ-ray observations [35] and the middle range—although the first to be proposed as a PBH dark-matter candidate [17]—is under tension because such PBHs would be captured by stars, whose neutron star or white-dwarf remnants would subsequently be destroyed by accretion [36]. One problem with PBHs in the IMBH range is that such objects would disrupt wide binaries in the Galactic disc. It was originally claimed that this would exclude objects above 400M [37] but more recent studies may reduce this mass [38], so the narrow window between the microlensing and wide-binary bounds is shrinking.（※） Nevertheless, this suggestion is topical because PBHs in the IMBH range could naturally arise in the inflationary scenario [39] and might also explain the sort of massive black-hole mergers observed by LIGO [40]. The suggestion that LIGO could detect gravitational waves from a population of IMBHs comprising the dark matter was originally proposed in the context of the Population III “VMO” scenario by Bond & Carr [41]. This is now regarded as unlikely, since the precursor stars would be baryonic and therefore subject to the BBNS constraint, but the same possibility applies for IMBHs of primordial origin.

• PBH质量函数会有小质量的“尾巴”，而不像人们过去认为的是monochromatic（单色的）
• 问题①：是否有存在一个质量窗口，其中的PBH能提供所有的暗物质？问题②（※）：If there is no mass scale at which PBHs could provide all the dark matter for a nearly monochromatic mass function, could they still provide it by being spread out in mass?

• 本文主要讨论三个质量范围的PBH

INTRODUCTION TO PBH FORMATION

• 给出PBH质量与时间的函数
• 啥是horizon mass？
• 介绍不同的膨胀情景(inflationary scenarios)，如"blue" fluctuation(decrease，文献), "designer" inflation(peaks on some scale, 文献),"waterfall" scenario文献，这些是不均匀性的来源
• 无论何种inhomogeneities：压强减小 → PBH形成增强 即使没有inhomogeneity也可自发产生：①bubble collision; ②cosmic string和domain wall塌陷

PRIMORDIAL BLACK HOLES AS DARK MATTER

原文：https://www.cnblogs.com/yjmphysics/p/11627600.html