论文标题
原始非高斯性直至所有订单：理论方面和对原始黑洞模型的影响
Primordial non-gaussianity up to all orders: theoretical aspects and implications for primordial black hole models
论文作者
论文摘要
我们开发了一种精确的形式主义，用于计算在曲率扰动场中存在局部非高斯（NG）的情况下的原始黑洞（PBH）。我们首次包括NG超越广泛使用的二次和立方近似值，并考虑一种完全通用的功能形式。采用压实函数的阈值统计数据，我们解决了狭窄和宽功率谱的丰度的计算。虽然我们的公式是通用的，但我们讨论了库瓦顿场的物理案例的现象学相关性的明确例子。我们仔细评估可以信任常规扰动方法的条件。在狭窄的功率谱的情况下，仅当将扰动膨胀推出超出二次顺序（取决于频谱宽度的最佳截断顺序）时，才会发生这种情况。最重要的是，我们证明，在考虑宽光谱时，扰动方法本质上存在缺陷，在这种情况下，仅非扰动计算才能捕获正确的结果。最后，我们描述了我们的结果与PBH的丰度与随机引力波（GW）背景与它们的形成有关的现象学相关性。由于NGS修改了产生给定的PBHS丰度并在大规模上增强PBHS生产所必需的扰动幅度，因此对这些效果进行建模对于将PBH方案连接到当前和未来GWS实验的特征至关重要。
We develop an exact formalism for the computation of the abundance of primordial black holes (PBHs) in the presence of local non-gaussianity (NG) in the curvature perturbation field. For the first time, we include NG going beyond the widely used quadratic and cubic approximations, and consider a completely generic functional form. Adopting threshold statistics of the compaction function, we address the computation of the abundance both for narrow and broad power spectra. While our formulas are generic, we discuss explicit examples of phenomenological relevance considering the physics case of the curvaton field. We carefully assess under which conditions the conventional perturbative approach can be trusted. In the case of a narrow power spectrum, this happens only if the perturbative expansion is pushed beyond the quadratic order (with the optimal order of truncation that depends on the width of the spectrum). Most importantly, we demonstrate that the perturbative approach is intrinsically flawed when considering broad spectra, in which case only the non-perturbative computation captures the correct result. Finally, we describe the phenomenological relevance of our results for the connection between the abundance of PBHs and the stochastic gravitational wave (GW) background related to their formation. As NGs modify the amplitude of perturbations necessary to produce a given PBHs abundance and boost PBHs production at large scales for broad spectra, modelling these effects is crucial to connect the PBH scenario to its signatures at current and future GWs experiments.
