CAS Key Laboratory for Researches in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026, China.
School of Astronomy and Space Science, University of Science and Technology of China, Hefei, Anhui 230026, China.
Phys Rev Lett. 2018 Aug 24;121(8):081306. doi: 10.1103/PhysRevLett.121.081306.
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 nonperturbative 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.
我们报告了一种新的现象，即原初密度涨落的共振效应，这是由具有振荡行为的声速参数引起的，它可能导致早期宇宙中原始黑洞的形成。对于一般的暴涨场，它可以产生原初密度涨落，它们的传播由声速平方的参数控制。一旦在暴涨期间，这个参数出现了振荡特征，那么在一个临界长度尺度上，暴涨场涨落会发生显著的非微扰共振效应，这导致了原初功率谱中的显著峰值。通过这种稳健的机制，可以产生具有特定质量函数的原始黑洞，并且在相当大的参数范围内，原始黑洞的数量足以构成暗物质。
