# Dark Matter Signatures of Supermassive Black Hole Binaries

## TL;DR

This paper explores how supermassive black hole binaries can create dense dark matter clumps near SMBHs through gravitational interactions, potentially detectable via gravitational waves and electromagnetic signals.

## Contribution

It introduces a novel mechanism linking SMBH binaries to dense dark matter clumps and their observable signatures.

## Key findings

- Dark matter density can be significantly enhanced near SMBHs due to binary interactions.
- The resulting dark matter clumps may produce detectable gravitational waves with LISA.
- Dark matter annihilation in these clumps could generate observable electromagnetic signals.

## Abstract

A natural consequence of the galaxy formation paradigm is the existence of supermassive black hole (SMBH) binaries. Gravitational perturbations from a far-away SMBH companion can induce high orbital eccentricities on dark matter particles orbiting the primary SMBH via the eccentric Kozai-Lidov mechanism. This process yields an influx of dark matter particles into the primary SMBH ergosphere, where test particles linger for long timescales. This influx results in high self-gravitating densities, forming a dark matter clump that is extremely close to the SMBH. In such a situation, the gravitational wave emission between the dark matter clump and the SMBH is potentially detectable by LISA. If dark matter self-annihilates, the high densities of the clump will result in a unique co-detection of gravitational wave emission and high energy electromagnetic signatures.