Primordial Black Holes from Sound Speed Resonance during Inflation
Abstract
We report on a novel phenomenon of the resonance effect of primordial density perturbations arisen from a sound speed parameter with an oscillatory behavior, which can generically lead to the formation of primordial black holes in the early Universe. For a general inflaton field, it can seed primordial density fluctuations and their propagation is governed by a parameter of sound speed square. Once if this parameter achieves an oscillatory feature for a while during inflation, a significant non-perturbative resonance effect on the inflaton field fluctuations takes place around a critical length scale, which results in significant peaks in the primordial power spectrum. By virtue of this robust mechanism, primordial black holes with specific mass function can be produced with a sufficient abundance for dark matter in sizable parameter ranges.
Keywords
Cite
@article{arxiv.1805.03639,
title = {Primordial Black Holes from Sound Speed Resonance during Inflation},
author = {Yi-Fu Cai and Xi Tong and Dong-Gang Wang and Sheng-Feng Yan},
journal= {arXiv preprint arXiv:1805.03639},
year = {2018}
}
Comments
6 pages, 4 figures; v2: figures replotted with corrections, analysis extended, version accepted by Phys.Rev.Lett