Rapid Dark Growth of Seed Black Holes in Self-Interacting Dark Matter
Abstract
The rapid emergence of massive black holes in the early Universe, possibly related to Little Red Dots, challenges conventional growth from light seeds. Dark-matter accretion offers a distinct route, and self-interacting dark matter (SIDM) makes it possible by behaving as a collisional fluid. We show that gas inflow can drive strong local contraction of an SIDM halo, assembling a dense reservoir around a pre-existing black-hole seed. The seed then enters a rapid dark-growth phase and can gain several orders of magnitude in mass within less than $1$ Myr before transitioning to slower accretion. We self-consistently follow this process by solving the spherical Euler equations with SIDM self-gravity, collisional heat transport, and an absorbing black-hole sink, rather than imposing an accretion history. The growth depends most strongly on halo mass, with weaker sensitivity to inflowing gas fraction, nuclear size, and seed mass. Gas-inflow-driven SIDM accretion therefore provides an efficient pathway for producing massive black holes in the early Universe.
Related
- Little Red Dots as a Transient Phase of Self-Interacting Dark Matter Assisted Black Hole Growth
- Rapid Growth of Intermediate-Mass Black Holes through Disk-induced Stellar Disruptions
- Orbital Migration of Interacting Stellar Mass Black Holes in Disks around Supermassive Black Holes. III. Mass Distribution of Hierarchical Mergers
- Massive black holes seeded by dark matter: Implications for little red dots and gravitational wave signatures
- Search for subsolar primordial black holes in low mass-ratio binaries with LIGO-Virgo O2 data and implications for the primordial black hole dark matter fraction
BibTeX
@misc{rong2026rapid,
title = {{Rapid Dark Growth of Seed Black Holes in Self-Interacting Dark Matter}},
author = {Yu Rong and Shuang-Nan Zhang and Jian-Min Wang and Junxian Wang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.20022},
eprint = {2609.20022},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.20022},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Rapid Dark Growth of Seed Black Holes in Self-Interacting Dark Matter
AU - Yu Rong
AU - Shuang-Nan Zhang
AU - Jian-Min Wang
AU - Junxian Wang
PY - 2026
DA - 2026/09/17
PB - arXiv
DO - 10.48550/arxiv.2609.20022
UR - https://arxiv.org/abs/2609.20022
AB - The rapid emergence of massive black holes in the early Universe, possibly related to Little Red Dots, challenges conventional growth from light seeds. Dark-matter accretion offers a distinct route, and self-interacting dark matter (SIDM) makes it possible by behaving as a collisional fluid. We show that gas inflow can drive strong local contraction of an SIDM halo, assembling a dense reservoir around a pre-existing black-hole seed. The seed then enters a rapid dark-growth phase and can gain several orders of magnitude in mass within less than $1$ Myr before transitioning to slower accretion. We self-consistently follow this process by solving the spherical Euler equations with SIDM self-gravity, collisional heat transport, and an absorbing black-hole sink, rather than imposing an accretion history. The growth depends most strongly on halo mass, with weaker sensitivity to inflowing gas fraction, nuclear size, and seed mass. Gas-inflow-driven SIDM accretion therefore provides an efficient pathway for producing massive black holes in the early Universe.
ER -