AI 中文总结
研究 JWST发现的“小红点”对标准模型构成挑战的问题，提出由QCD时代热历史预测的强聚集原初黑洞群体实现组装LRD尺度种子构型的方法，贡献在于明确其引力波特征及相关参数，可用于鉴别LRDs是否为PBH - 核播种黑洞。
AI 中文摘要
詹姆斯·韦伯太空望远镜（JWST）在红移\(z\simeq5 - 9\)的化学性质近乎原始的宿主星系中发现了紧凑、红色、超大质量的吸积黑洞，即所谓的“小红点”（LRDs），这对标准的重种子模型提出了挑战。我们表明，由 QCD 时代热历史预测的具有广泛质量函数的强聚集原初黑洞（PBH）群体自然地实现了组装 LRD 尺度种子的构型：一个中等质量的 PBH 核\(M_{\rm BH}\sim10^3\) - \(10^5\,M_\odot\)，在几秒差距内被一群嵌入致密重子气体中的轻（\(m\sim30\,M_\odot\)）PBH 包围。气体动力学摩擦使损失锥保持满态并使核心收缩，因此这群 PBH 在\(t_{\rm seed}\sim10 - 50\) Myr 内下沉并被吞噬，远早于\(z\sim10 - 15\)时的宇宙时间。由于一开始就存在一个重核，捕获发生在极端质量比\(q\sim10^{-4}\) - \(10^{-2}\)：残余物能抵抗引力反冲，并且每次捕获在引力波（GW）发射下达到最内稳定轨道，辐射约\(0.06\,m c^2\)，使得组装效率\(\zeta\simeq0.06\)，与\(M_{\rm BH}\)无关。叠加的群聚吸积形成一个随机背景\(\Omega_{\rm GW} h^2\sim10^{-13}\) - \(10^{-11}\)，其形状为\(\Omega_{\rm GW}\propto f^{2/3}\)，在气体解耦频率以下截断，并在\(z_f\simeq12\)时，对于\(10^5\,M_\odot\)的核，在\(f_{\rm ring}(M_{\rm BH})\simeq13\) mHz 处有一个铃宕“梳状”结构，对于\(10^3\,M_\odot\)的核，在\(f_{\rm ring}(M_{\rm BH})\simeq1.3\) Hz 处有一个铃宕“梳状”结构。少数质量相当的核 - 核合并则是可单独分辨的 LISA/分赫兹源。检测并将这些特征与相同质量的直接形成的 PBH 种子区分开来，将确定 LRDs 为 PBH 核播种的黑洞。
英文摘要
The James Webb Space Telescope (JWST) has revealed compact, red, overmassive accreting black holes - the so-called ``Little Red Dots'' (LRDs) - in chemically near-pristine hosts at $z\simeq5 - 9$, straining standard heavy-seed models. We show that a population of strongly clustered primordial black holes (PBH) with a broad mass function predicted by a QCD-epoch thermal history naturally realizes the configuration that assembles LRD-scale seeds: an intermediate-mass PBH \emph{nucleus} $M_{\rm BH}\sim10^3$-$10^5\,M_\odot$ surrounded, within a few parsecs, by a swarm of light ($m\sim30\,M_\odot$) PBHs embedded in dense baryonic gas. Gas dynamical friction keeps the loss cone full and lets the core contract, so the swarm sinks and is swallowed on $t_{\rm seed}\sim10$-50 Myr, well inside the cosmic time at $z\sim10$-$15$. Because a heavy nucleus is present \emph{ab initio}, the captures occur at extreme mass ratio $q\sim10^{-4}$-$10^{-2}$: the remnant is retained against gravitational recoil, and each capture reaches the innermost stable orbit under gravitational-wave (GW) emission, radiating $\simeq0.06\,m c^2$ so that the assembly efficiency is $ζ\simeq0.06$ independent of $M_{\rm BH}$. The superposed swarm inspirals form a stochastic background $Ω_{\rm GW} h^2\sim10^{-13}$-$10^{-11}$ with a $Ω_{\rm GW}\propto f^{2/3}$ shape truncated below the gas-decoupling frequency and topped by a ringdown ``comb'' at $f_{\rm ring}(M_{\rm BH})\simeq13$ mHz for $10^5\,M_\odot$ and $\simeq1.3$ Hz for $10^3\,M_\odot$ nuclei at $z_f\simeq12$. The few comparable-mass nucleus-nucleus coalescences are instead individually resolvable LISA/deci-Hz sources. Detection, and discrimination of these signatures from a directly formed PBH seed of the same mass, would identify the LRDs as PBH-nucleus seeded black holes.
Comments7 pages
