19 Jun 2024 | Theodoros Papanikolaou, Shreya Banerjee, Yi-Fu Cai, Salvatore Capozziello, Emmanuel N. Saridakis
The paper presents a novel model-independent mechanism for primordial black hole (PBH) formation within the context of non-singular matter bouncing cosmology. The authors consider a short transition from the matter contracting phase to the Hot Big Bang (HBB) expanding Universe, where enhanced curvature perturbations on very small scales can collapse and form PBHs. These PBHs could potentially explain the totality of dark matter, lying within the observationally unconstrained asteroid-mass window. Additionally, the induced gravitational waves (GWs) from the collapse of these PBHs can be detectable by future experiments such as SKA, PTAs, LISA, and ET, providing a new way to probe the bouncing nature of the early Universe. The paper is organized into several sections, covering the background dynamics, perturbation dynamics, curvature power spectrum, PBH formation, and the induced GWs. The authors derive analytical expressions for the curvature power spectrum and calculate the PBH abundance using peak theory. They also discuss the scaling behavior of the curvature power spectrum and the formation threshold of PBHs. Finally, they explore the stochastic GW background induced by the enhanced curvature perturbations and provide predictions for the GW spectrum, which can be tested by upcoming GW experiments.The paper presents a novel model-independent mechanism for primordial black hole (PBH) formation within the context of non-singular matter bouncing cosmology. The authors consider a short transition from the matter contracting phase to the Hot Big Bang (HBB) expanding Universe, where enhanced curvature perturbations on very small scales can collapse and form PBHs. These PBHs could potentially explain the totality of dark matter, lying within the observationally unconstrained asteroid-mass window. Additionally, the induced gravitational waves (GWs) from the collapse of these PBHs can be detectable by future experiments such as SKA, PTAs, LISA, and ET, providing a new way to probe the bouncing nature of the early Universe. The paper is organized into several sections, covering the background dynamics, perturbation dynamics, curvature power spectrum, PBH formation, and the induced GWs. The authors derive analytical expressions for the curvature power spectrum and calculate the PBH abundance using peak theory. They also discuss the scaling behavior of the curvature power spectrum and the formation threshold of PBHs. Finally, they explore the stochastic GW background induced by the enhanced curvature perturbations and provide predictions for the GW spectrum, which can be tested by upcoming GW experiments.