Detecting Primordial Black Hole Relics with Gravitational Waves
Analysis
This paper proposes a novel method to detect primordial black hole (PBH) relics, which are remnants of evaporating PBHs, using induced gravitational waves. The study focuses on PBHs that evaporated before Big Bang nucleosynthesis but left behind remnants that could constitute dark matter. The key idea is that the peak positions and amplitudes of the induced gravitational waves can reveal information about the number density and initial abundance of these relics, potentially detectable by future gravitational wave experiments. This offers a new avenue for probing dark matter and the early universe.
Key Takeaways
- •PBH relics, remnants of evaporating PBHs, are considered as potential dark matter candidates.
- •Induced gravitational waves from the inhomogeneous distribution of PBH relics can be used to determine their number density and initial abundance.
- •The peak frequency of the gravitational waves is related to the fraction of PBH relics in dark matter.
- •The amplitude of the gravitational waves carries information about the initial PBH abundance.
- •Planned gravitational wave experiments may be able to detect these signals.
Reference
“The peak frequency scales as $f_{ ext {relic }}^{1 / 3}$ where $f_{ ext {relic }}$ is the fraction of the PBH relics in the total DM density.”