AI 中文总结
研究单场模型中从慢滚经超慢滚进入暴胀期时原初黑洞形成，用数值模拟跟踪场涨落，发现三种不同结果，测量坍缩阈值并比较，表明非吸引子模型中PBH丰度需依完整分布制定，不同通道分别处理。
AI 中文摘要
我们研究了单场模型中的原初黑洞（PBH）形成，该模型从慢滚阶段经过一个瞬态超慢滚阶段进入暴胀期。利用非线性数值相对论模拟跟踪局部的、最初为次哈勃场涨落在非吸引子转变过程中的变化，确定由此产生的超哈勃曲率分布，并随后演化它们在暴胀期的重新进入。在此探索的初始构型集合中，我们发现了三种定性不同的结果，即一个被困在暴胀中的区域、一个正曲率过密区和一个由过密壳界定的负曲率空洞。每种情况都可能通过不同的物理机制形成PBH。对于过密区和空洞通道中各一个选定的分布，我们测量了坍缩阈值并将它们与正弦分布的阈值进行比较。比较表明，单独的中心曲率或峰值线性压缩都不能提供与分布或通道无关的坍缩判据。因此，非吸引子模型中的PBH丰度必须根据完整分布来制定，对捕获区、过密区和空洞通道分别进行处理。
英文摘要
We study primordial black-hole (PBH) formation in a single-field model which passes from slow roll, through a transient ultra-slow-roll phase, into kination. Nonlinear numerical-relativity simulations are used to follow localised, initially sub-Hubble field fluctuations across the non-attractor transition, to determine the resulting super-Hubble curvature profiles, and subsequently to evolve their re-entry during kination. Within the set of initial configurations explored here, we find three qualitatively distinct outcomes, namely a patch which remains trapped in inflation, a positive-curvature overdensity, and a negative-curvature void bounded by an overdense shell. Each may form a PBH, although by a different physical mechanism. For one selected profile in each of the overdense and void channels, we measure collapse thresholds and compare them with thresholds for sinc profiles. The comparison shows that neither the central curvature nor the peak linear compaction alone provides a profile- or channel-independent collapse criterion. PBH abundances in non-attractor models must therefore be formulated in terms of the distribution of complete profiles, with the trapped, overdense, and void channels treated separately.
Comments5 pages, 4 figures, + Supplemental Material
