Imprint of Accretion Disk-Induced Migration on Gravitational Waves from Extreme Mass Ratio Inspirals

TL;DR

This paper investigates how accretion disks influence gravitational wave signals from extreme mass ratio inspirals, suggesting that LISA could detect disk effects and infer disk properties.

Contribution

It introduces a phenomenological model for disk-induced angular momentum transport and demonstrates its impact on gravitational wave phase evolution.

Findings

Disk torques cause detectable phase shifts in gravitational waves.

Disk-modified waveforms have distinct frequency trends from vacuum signals.

LISA can potentially identify and characterize accretion disks around supermassive black holes.

Abstract

We study the effects of a thin gaseous accretion disk on the inspiral of a stellar--mass black hole into a supermassive black hole. We construct a phenomenological angular momentum transport equation that reproduces known disk effects. Disk torques modify the gravitational wave phase evolution to detectable levels with LISA for reasonable disk parameters. The Fourier transform of disk-modified waveforms acquires a correction with a different frequency trend than post-Newtonian vacuum terms. Such inspirals could be used to detect accretion disks with LISA and to probe their physical parameters.