Dr. Zhu Yi from the Laboratory of Gravitational Waves and Cosmology and his cooperator use the observational data of primordial black holes and stochastic gravitational wave background to constrain the primordial curvature perturbations at small scales (as shown in the figure below), effectively making up for the lack of observation constraints of the primordial curvature perturbation at small scales.

The quantum fluctuations of space-time generated in cosmic inflation are the seeds of the formation of the large-scale structure of the Universe. The study of the primordial curvature perturbations, caused by the quantum fluctuations of space-time, can help to understand the formation mechanism of the large-scale structure of the Universe. At present, the observational constraints of the primordial curvature perturbations mainly come from the observation of the anisotropy of the cosmic microwave background radiation at a large scale; However, at small scales, there is a lack of effective observation constraints. The primordial curvature can produce primordial black holes and induced secondary gravitational waves.

The research was recently published in The European Physical Journal C, an international first-class academic journal, with the Advanced Institute of Natural Sciences of Beijing Normal University as the first affiliation. The link to the paper is https://link.springer.com/article/10.1140/epjc/s10052-023-11233-3.