Experimental Limits on Planetary Mass Primordial Black Hole Mergers

Abstract

The multi-mode acoustic gravitational wave experiment (MAGE) is a high-frequency gravitational wave detection experiment featuring cryogenic quartz bulk acoustic wave resonators operating as sensitive strain antennas in the MHz regime. After 61 days of non-continuous data collection, we present bounds on the observable merger rate density of primordial black hole binary systems of chirp mass $1.2\times 10^{-4}{M}_{\odot }<\mathcal{M}<1.7\times 10^{-9}{M}_{\odot }$. The maximum achieved limit on the merger rate density is $\mathcal{R}>1.3\times 10^{18}{\mathrm{kpc}}^{-3}{\mathrm{yr}}^{-1}$ which corresponds to constraining yearly mergers to a distance of reach on the order of the solar system, or $1.0\times 10^{-6}$ kpc during the observational period. In addition, we exclude significantly rare and strong events similar to those observed in previous predecessor experiments as non-gravitational background signals, utilising coincident analysis between multiple detectors.

Accepted: https://journals.aps.org/prl/accepted/10.1103/c1kj-rj3c