论文标题
聚类对原始黑洞微透镜约束的影响
Effect of clustering on primordial black hole microlensing constraints
论文作者
论文摘要
恒星微透镜观测紧密地约束质量范围$（10^{ - 11} -10^{3}）m _ {\ odot} $中的紧凑型对象。原始黑洞（PBHS）形成簇，有人认为这些微透明的约束被削弱或逃避。对于最常见的PBH形成机制，通货膨胀产生的大高斯曲率扰动的崩溃充分扩展，以使其内部的PBHS充当单个镜头。我们发现，如果群集的典型质量足够大，$ \ gtrsim 10^{6} m _ {\ odot} $，那么事件持续时间分布可能在最短的持续时间内与光滑的暗物质分布产生的持续时间显着偏离。因此，观察到的事件数量的概率分布是非波斯多尼亚人，以较低的值达到峰值，尾巴扩展到大量事件。但是，对于由大通货膨胀扰动崩溃而形成的PBH，典型集群预计将包含$ \ sim 10^{3} $ PBHS。在这种情况下，聚类的效果可忽略不计，除了在长达十年的恒星微透镜调查中探测的最庞大的PBH（$ M _ {\ rm PBH} \ sim 10^{3} M _ {\ odot} $）。
Stellar microlensing observations tightly constrain compact object dark matter in the mass range $(10^{-11} - 10^{3}) M_{\odot}$. Primordial Black Holes (PBHs) form clusters, and it has been argued that these microlensing constraints are consequently weakened or evaded. For the most commonly studied PBH formation mechanism, the collapse of large gaussian curvature perturbations generated by inflation, the clusters are sufficiently extended that the PBHs within them act as individual lenses. We find that if the typical mass of the clusters is sufficiently large, $ \gtrsim 10^{6} M_{\odot}$, then the event duration distribution can deviate significantly from that produced by a smooth dark matter distribution, in particular at the shortest durations. As a consequence of this, the probability distribution of the number of observed events is non-Poissonian, peaking at a lower value, with an extended tail to large numbers of events. However, for PBHs formed from the collapse of large inflationary perturbations, the typical cluster is expected to contain $\sim 10^{3}$ PBHs. In this case the effect of clustering is negligibly small, apart from for the most massive PBHs probed by decade-long stellar microlensing surveys ($M_{\rm PBH} \sim 10^{3} M_{\odot}$).
