Detection Potential of Gravitational Waves from Primordial Black Hole Evaporation

Researchers have explored the potential of detecting gravitational waves originating from the evaporation of primordial black holes in the early universe, particularly within the context of theories involving large extra dimensions. The study, conducted by Aurora Ireland, Stefano Profumo, and Jordan Scharnhorst, focuses on the emission of brane-localized gravitons during the Hawking evaporation of ultra-light primordial black holes.

The researchers computed greybody factors for particles of various spins emitted both on the brane and in the bulk, assuming most emissions occur during the Schwarzschild phase. Their findings indicate that the peak frequency of these gravitational waves can be significantly lowered when considering large extra dimensions, making the signal detectable by planned high-frequency gravitational wave detectors.

The study suggests that with optimal parameters, the peak frequency of the gravitational waves could plateau in the sub-MHz range. This frequency range falls within the capabilities of upcoming high-frequency gravitational wave detectors, potentially allowing for the detection of these signals once the sensitivity of these detectors improves.

The implications of this research are significant, as detecting gravitational waves from primordial black hole evaporation could provide insights into the early universe and the nature of large extra dimensions. This could further our understanding of fundamental physics and the conditions of the early cosmos.