标题： 利用VERITAS的存档数据对原初黑洞的蒸发速率进行限制 显示英文标题

标题： Constraining the evaporation rate of primordial black holes using archival data from VERITAS

摘要： 原初黑洞（PBHs）被认为是由于宇宙早期的密度涨落形成的。 据推测，质量为$\sim 5 \times 10^{14} \mathrm{\ g}$或更小的PBHs到目前为止已经通过释放霍金辐射而蒸发掉了。 然而，初始质量为$10^{15} \mathrm{\ g}$的PBHs目前仍在蒸发。 在过去几年中，使用地面伽马射线仪器对以爆发形式从PBHs发出的极高能（VHE；E $>$ 100 GeV）伽马射线进行了搜索。 然而，迄今为止尚未报告有关检测到PBHs的极高能辐射的观测证据。 之前，利用VERITAS伽马射线天文台在2009年至2012年间收集的750小时存档数据计算了PBHs的速率密度上限。 我们将用2012年至2017年间收集的额外数据来扩充这项研究。 除了更多的数据，新数据的较低能量阈值将有助于提高我们本地区域内PBHs蒸发速率的上限。 这项工作仍在进行中，因此我们只会报告对PBH蒸发速率密度上限的预期变化。 显示英文摘要

摘要： Primordial black holes (PBHs) are thought to have been formed as a result of density fluctuations in the very early Universe. It is suggested that PBHs of mass $\sim 5 \times 10^{14} \mathrm{\ g}$ or less have evaporated through the release of Hawking radiation by the present day. However, PBHs of initial mass $10^{15} \mathrm{\ g}$ should still be evaporating at the present epoch. Over the past few years, very high-energy (VHE; E $>$ 100 GeV) gamma-ray emission from PBHs in the form of a burst has been searched for using ground-based gamma-ray instruments. However, no observational evidence has been reported on the detection of VHE emission from PBHs yet. Previously, an upper limit on the rate density of PBHs was calculated using 750 hours of archival data taken between 2009 and 2012 by the VERITAS gamma-ray observatory. We will augment this study with additional data taken between 2012 and 2017. In addition to more data, the lower energy threshold on the newer data will help to produce an improved upper limit on the rate at which PBHs are evaporating in our local neighborhood. This work is still in progress, therefore we will only report an expected change to the upper limit on the rate density of PBH evaporation.