The Gravitational Spectral Radio Forest: A Signature of Primordial Black Holes

2026/05/13 by P. George Christopher, K. Hari, S. Shankaranarayanan · 1 voice
Physics and Astronomy · #astro-ph.CO #astro-ph.GA #gr-qc #hep-th #physics.atm-clus

paper · pdf · doi:10.1142/s0218271826400018

Abstract

We propose a novel gravitational signature to detect Primordial Black Hole (PBH) dark matter by treating interstellar hydrogen as a quantum sensor for spacetime curvature. Focusing on H II regions, we demonstrate that the Riemann tidal tensor of an asteroid-mass PBH induces a symmetric splitting of the 2P_3/2 state in bound hydrogen atoms. This relativistic effect redistributes 9.9 GHz absorption line into a gravitational spectral radio forest with a bandwidth ∼ 2 GHz. By accounting for active accretion of Hydrogen atoms and the resulting density-squared emission measure within the Bondi radius, we find a relatively enhanced absorption spectrum. This feature presents a concrete, high-contrast target for upcoming radio-surveys to constrain PBH populations in the dark matter sector.

Citations

• Primordial black holes: constraints, potential evidence and prospects

Cited by

• Primordial Black Holes: A Review of Formation and Evolution

Discussions

• 1st Prize 2026 of the Gravity Research Foundation, GRF. 'The Gravitational Spectral Radio Forest: A Signature of Primordial Black Holes' Novel gravitational signature to detect PBH dark matter by trea [bsky, 1 points, 0 comments]

Related

• Gravitation Wave signal from Asteroid mass Primordial Black Hole Dark Matter
• Black Hole Phenomenology and Dark Matter Searches
• Primordial black holes in the Dark Ages: Observational prospects for future 21cm surveys
• Gravitational wave signatures of primordial black hole accretion during early matter domination
• On the detectability of primordial black holes in the Galaxy