Primordial Black Holes (PBHs) serve as a unique probe to the physics of the early Universe, particularly inflation. In light of this, we study the formation of PBHs by the collapse of overdense perturbations generated during a model of warm inflation. For our model, we find that the primordial curvature power spectrum is red-tilted (spectral index $n_s 1$) for the small PBH scales (large $k$), with a sufficiently large amplitude of the primordial curvature power spectrum required to form PBHs. These features originate because of the inflaton's coupling with the other fields during warm inflation. We discuss the role of the inflaton dissipation to the enhancement in the primordial power spectrum at the PBH scales. We find that for some parameter range of our warm inflation model, PBHs with mass $\sim 10^3$ g can be formed with significant abundance. Such tiny mass PBHs have a short lifetime $\sim 10^{-19}$ s and would have evaporated into Hawking radiation in the early Universe. Further in this study, we discuss the evaporation constraints on the initial mass fraction of the generated PBHs and the possibility of Planck mass PBH relics to constitute the dark matter.

中文翻译：

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由暖膨胀形成的原始黑洞

原始黑洞 (PBH) 是对早期宇宙物理学（尤其是暴胀）的独特探索。有鉴于此，我们研究了热膨胀模型期间产生的过度密集扰动的崩溃导致 PBH 的形成。对于我们的模型，我们发现对于小 PBH 尺度（大 $k$），原始曲率功率谱呈红色倾斜（光谱指数 $n_s 1$），需要形成足够大的原始曲率功率谱振幅PBH。这些特征源于在暖胀过程中暴胀子与其他场的耦合。我们讨论了暴胀子耗散对 PBH 尺度原始功率谱增强的作用。我们发现对于暖通胀模型的某些参数范围，可以形成具有显着丰度的质量为 $\sim 10^3$ g 的 PBH。如此微小的 PBH 寿命很短，只有 $\sim 10^{-19}$ s，并且会在早期宇宙中蒸发成霍金辐射。在本研究中，我们进一步讨论了对生成的 PBH 的初始质量分数的蒸发约束以及普朗克质量 PBH 遗迹构成暗物质的可能性。