# Tidal resonance in extreme mass-ratio inspirals

## TL;DR

This paper introduces tidal resonances in EMRIs caused by nearby stellar objects, which can influence gravitational wave signals and reveal details about the environment near galactic-center black holes.

## Contribution

It identifies a new class of resonances in EMRIs, extending the understanding of their dynamics and potential observational signatures.

## Key findings

- Tidal resonances are common in EMRIs.
- They affect the phase evolution of gravitational waveforms.
- Potential to probe stellar environments near black holes.

## Abstract

We describe a new class of resonances for extreme mass-ratio inspirals (EMRIs): tidal resonances, induced by the tidal field of nearby stars or stellar-mass black holes. A tidal resonance can be viewed as a general relativistic extension of the Kozai-Lidov resonances in Newtonian systems, and is distinct from the transient resonance already known for EMRI systems. Tidal resonances will generically occur for EMRIs. By probing their influence on the phase of an EMRI waveform, we can learn about the tidal environmental of the EMRI system, albeit at the cost of a more complicated waveform model. Observations by LISA of EMRI systems therefore have the potential to provide information about the distribution of stellar-mass objects near their host galactic-center black holes.