Massive Black Holes Seeded by Dark Matter -- Implications for Little Red Dots and Gravitational Wave Signatures

TL;DR

This paper proposes a dark matter-driven model for the formation of supermassive black holes, explaining high-redshift observations and predicting gravitational wave signals detectable by future observatories.

Contribution

It introduces a dissipative self-interacting dark matter model that naturally forms massive black hole seeds, aligning with recent astronomical observations and GW constraints.

Findings

Reproduces billion-solar-mass quasars and faint active galactic nuclei.

Suggests a large population of dormant SMBHs due to duty-cycle requirements.

Predicts detectable gravitational wave signals from SMBH mergers.

Abstract

Observations of supermassive black holes (SMBHs) at high redshifts challenge standard seeding scenarios. We examine a dissipative self-interacting dark matter (dSIDM) model in which gravothermal collapse leads to the formation of massive BH seeds ab initio. We utilize a semi-analytical framework to predict properties of the dSIDM-seeded SMBH population. Billion solar mass quasars are reproduced along with low-mass faint active galactic nuclei (known as little red dots) with SMBH-to-galaxy stellar mass ratios consistent with recent James Webb Space Telescope observations. To match the abundance of the observed bright quasars, a percent-level duty-cycle is suggested, implying a large population of dormant SMBHs. The gravitational wave (GW) signals from mergers of these massive SMBHs can be detected by LISA while remaining within the NANOGrav constraints on the GW background. These results provide testable signatures of DM-driven SMBH formation, offering a pathway to probe hidden-sector physics through SMBH and GW observables.