PBH Dark Matter from Ultra-Slow-Roll Inflation in Horndeski Gravity
Analysis
This paper investigates the production of primordial black holes (PBHs) as a dark matter candidate within the framework of Horndeski gravity. It focuses on a specific scenario where the inflationary dynamics is controlled by a cubic Horndeski interaction, leading to an ultra-slow-roll phase. The key finding is that this mechanism can amplify the curvature power spectrum on small scales, potentially generating asteroid-mass PBHs that could account for a significant fraction of dark matter, while also predicting observable gravitational wave signatures. The work is significant because it provides a concrete mechanism for PBH formation within a well-motivated theoretical framework, addressing the dark matter problem and offering testable predictions.
Key Takeaways
- •Investigates Primordial Black Hole (PBH) dark matter within Horndeski gravity.
- •Proposes an ultra-slow-roll phase driven by a cubic Horndeski interaction.
- •Amplifies the curvature power spectrum on small scales, potentially forming asteroid-mass PBHs.
- •PBHs could account for a substantial fraction of dark matter.
- •Predicts potentially observable scalar-induced gravitational-wave signatures.
“The mechanism amplifies the curvature power spectrum on small scales without introducing any feature in the potential, leading to the formation of asteroid-mass PBHs.”