Radio Emission from High-Frequency Gravitational Wave Point Sources

High-frequency gravitational waves (HFGWs) in the MHz to GHz regime can convert into radio photons in the presence of astrophysical magnetic fields through the inverse Gertsenshtein effect. We show that existing radio telescopes like CHIME and FAST are excellent tools for detecting HFGW sources, significantly outperforming many existing experiments at detecting primordial black hole (PBH) mergers, the most realistic sources of transient HFGWs. Radio telescopes are also uniquely sensitive to sources of monochromatic HFGW emission, such as ultralight boson clouds formed through superradiance around PBHs, and are likely to have excellent sensitivity to generic sources of detectable HFGWs.

arXiv:2606.09968