# Early formation of supermassive black holes via dark matter self-interactions

## TL;DR

This paper investigates how a small fraction of self-interacting dark matter can lead to the early formation of supermassive black holes at high redshifts using N-body simulations, challenging previous fluid-based models.

## Contribution

It introduces N-body gravitational simulations to study dark matter self-interactions and their role in early supermassive black hole formation, providing a more detailed analysis than prior fluid models.

## Key findings

- Self-interacting dark matter can seed supermassive black holes at high redshifts.
- A specific parameter space allows for early black hole formation consistent with observations.
- Both elastic and dissipative scattering processes influence black hole growth.

## Abstract

The existence of supermassive black holes at high redshifts ($z\sim7$) is difficult to accommodate in standard astrophysical scenarios. It has been shown that dark matter models with a subdominant self-interacting component are able to produce early seeds for supermassive black holes through the gravothermal catastrophe. Previous studies used a fluid equation approach, requiring some limiting assumptions. Here we reconsider the problem using $N$-body gravitational simulations starting from the formation of the initial dark matter halo. We consider both elastic and dissipative scattering, and elucidate the interplay between the dark matter microphysics and subsequent accretion of the black hole needed to match the properties of observed high redshift supermassive black holes. We find a region of parameter space in which a small component of self-interacting dark matter can produce the observed high redshift supermassive black holes.